
Citation: | Yanxin Sui, Huili Liang, Wenxing Huo, Xiaozhi Zhan, Tao Zhu, Zengxia Mei. Flexible UV detectors based on in-situ hydrogen doped amorphous Ga2O3 with high photo-to-dark current ratio[J]. Materials Futures, 2024, 3(1): 015701. DOI: 10.1088/2752-5724/ad19e1 |
Deep ultraviolet (UV) detection has broad applications in the field of space communication, flame pre-warning, biomedicine, missile guidance, ozone monitoring and power system safety [1-3]. As a natural deep UV detecting material, amorphous Ga2O3 (a-Ga2O3) owns many advantages such as suitable bandgap of 4.9 eV with no need of intentional alloying, comparable photoresponsivity with its crystalline counterpart, homogeneity without crystal grains and large-area preparation at room temperature, making it a promising candidate in practical applications. [4-8] To feasibly capture ultra-weak UV light in most usage scenarios, a competent UV photodetector (PD) must possess performance with low dark current and high responsivity simultaneously, that is, high photo-to-dark current ratio (PDCR). However, the ultra-high responsivity (usually in the level of hundreds of A/W) of a-Ga2O3 UV PDs with simple metal-semiconductor-metal (MSM) structure is always accompanied by a high dark current due to the presence of abundant oxygen vacancy (VO) defects [5, 9], which is generally believed as a donor in oxide materials and a tunneling defect at the metal/semiconductor Schottky contact [10, 11]. Bottom-gate thin-film transistor architecture has been constructed to electrically deplete the electrons in a-Ga2O3 channel by a negative gate voltage, [12, 13] but the fabrication process is more complicated compared with two-terminal devices. Therefore, it is worthwhile to develop a new strategy with chemical doping of a-Ga2O3 thin films to decrease the dark current while maintaining high photocurrent using simple MSM structure.
As a stubborn residual gas in vacuum chamber, hydrogen is often unintentionally doped into semiconductor materials [14], which can greatly affect the electrical properties [15, 16]. According to hybrid functional calculations, these hydrogen atoms are considered as shallow donors and responsible for the observed n-type conductivity in
In this work, intentional hydrogen-doped a-Ga2O3 films have been fabricated on quartz and polyethylene naphtholate (PEN) substrates by radio frequency (rf) magnetron sputtering technique. By in-situ tuning hydrogen flux subtly during sputtering process, the dark current of the optimal device is significantly decreased by about two orders of magnitude, exhibiting an excellent capability to detect weak UV light. In addition, flexible UV PDs on PEN substrate demonstrate great robustness in bending states and fatigue tests with comparable photoresponse as those on quartz substrate.
Film growth: a-Ga2O3 films with thickness of 80-100 nm were deposited on quartz (500
Device fabrication: Ga2O3 UV PDs were constructed with a coplanar MSM structure by conventional UV-lithography and lift-off technology. 100 nm ITO was deposited to form the transparent interdigital electrodes. These electrodes have 75 pairs of fingers with 5
Material characterization: To determine the optical bandgap of these a-Ga2O3 films, transmittance spectrum was measured by using the Varian Cary 5000 UV-vis spectrophotometer. The surface morphology and roughness were evaluated by atomic force microscope (AFM, Bruker Dimension EDGE). X-ray diffractometer (XRD, Rigaku Smart Lab) was employed to confirm the amorphous nature of all the films. X-ray reflectivity (XRR) measurement was carried out on the same equipment to determine the density and thickness of all the films. Neutron reflection (NR) spectra were recorded using the non-polarized mode of multipurpose reflectometer, a time-of-flight neutron reflectometer (2.5 <
Device characterization: Keithley 6487 picoammeter was used to measure the dark current of all devices while Keithley 2400 was used to collect the electrical signals under light illumination. The light source was supplied by a hand-held 254 nm UV lamp. Photoresponsivity measurements were performed using a UV-enhanced Xenon lamp equipped with a monochromator, where optical power density is calibrated by a standard Si PD (Zolix).
As exhibited in figure 1(a), all the samples on quartz substrates show a high transmittance over 85% above 300 nm and a strong UV absorption below 250 nm. The variation of optical bandgap is shown in the inset of figure 1(a), indicating an ignorable influence of hydrogen content on the bandgap and an excellent capability of UV light detection. The AFM image of sample S1 is shown in figure 1(b) with the root mean square roughness of 0.425 nm. The incorporation of hydrogen does not degrade the surface morphology apparently compared with the pure a-Ga2O3 as displayed in figure S1. Figure 1(c) shows the grazing incident XRD curves of all the samples. No signature peak is observed except a wide envelope at 21.5, implying these thin films are amorphous without long-range order. In order to further explore the quality of the films, XRR measurement was carried out. By fitting the XRR experimental curves (figure 1(d)), the thickness as well as the mass density are determined as 84 nm/4.75 g cm-3, 85 nm/5.34 g cm-3, 93 nm/5.12 g cm-3 and 95 nm/4.80 g cm-3 for S0-S3, respectively. It can be found that the film density decreases while the thickness increases as the hydrogen flux rises from S1 to S3, implying that the in-situ hydrogen doping may change the local arrangement of atoms and cause an expansion of the nearest bond length in a-Ga2O3.
To confirm the existence of hydrogen in a-Ga2O3 thin films, NR measurement was employed since hydrogen can be easily detected with this technique. By using the GenX reflectometry analysis package, the experimental NR curves can be fitted to get the parameters of scattering length ( where where |
(1) |
A two-layer model, including the interfacial transition layer and the main layer, was used to fit the experimental NR curves. This model is consistent with the nucleation process of physical vapor deposition, yielding the best fitting curves with uniform SLD values in the main layer and steep steps at the interface as shown in figure 2. It can be found that the value of B gradually decreases with the increase of hydrogen fluxes, indicating that hydrogen is effectively incorporated into the films, agreeing well with secondary ion mass spectrometry result shown in figure S2. It should be emphasized that even though there is no intentional hydrogen doping, the value of B for S0 is still lower than the standard value (31.985) for stoichiometric Ga2O3, which probably due to the presence of VO defects in oxide thin films. [5] In addition, the value of D also decreases as the hydrogen flux increases, consistent with the XRR results shown in figure 1(c).
Based on the above thin films, UV PDs with simple MSM structure were fabricated to evaluate the impact of hydrogen on the photoresponse behavior. Figure 3(a) shows the I-V curves of the PDs in dark and under 254 nm UV light illumination. It can be clearly found that the photocurrent of S1 enhances several times while the dark current decreases nearly two orders of magnitude compared with S0, leading to a PDCR value larger than 107. This behavior is quite different with the fact that both the dark current and photocurrent will decrease simultaneously if only the interfacial barrier height is enhanced according to previous reports where oxygen gas is introduced [5, 10]. More carriers must be excited into the conduction band. Since the bandgap is almost unchanged by hydrogen doping (figure 1(a)), the most probable origin of the extra carriers should come from the sub-bandgap states. However, the response speed does not change significantly as shown in figure 3(b), further implying the existence of abundant deep level traps. Therefore, the improvement of the photocurrent is tentatively ascribed to the new sub-bandgap states related with hydrogen doping.
In order to quantitatively assess the photoelectric performance of the H doped a-Ga2O3 PDs, key figure-of-merits for UV PDs, such as responsivity ( where |
(3) |
( |
(5) |
Photoresponse spectra of all samples are recorded as shown in figure 3(c). Take the best sample S1 as an example. Its responsivity is as high as 3.20 104 A W-1 at around 254 nm, corresponding to the EQE of 1.57 107% and D of 5.28 1015 Jones, respectively. Such a high detectivity is attributed to the ultrahigh responsivity and ultralow dark current of the H-doped a-Ga2O3 UV PDs. In addition, the broadband photoresponse with a redshift of the peak position is observed even though the bandgap does not change a lot according to the transmittance spectra (figure 1(a)). The response from the longer wavelength should come from the excitation of the sub-bandgap states and band tails due to the presence of abundant defects and absence of long-range order. This phenomenon has been reported in a-IGZO and a-Ga2O3 thin films previously [4, 25].
Further, to investigate the stability of the devices, a long-term follow-up test of about 3 months was carried out. All devices are placed in the drying cabinet without any passivation or encapsulation treatments. From figure 3(d), it can be seen that the PDCR values of all the devices are maintained at the original level with a slight decrease after about 100 d, ensuring a long-term service of the H-doped a-Ga2O3 UV PDs.
The parameters of all the representative devices on sample S0-S3 are summarized in table 1. With the increase of hydrogen flux, the dark currents show a trend of first decreasing and then increasing while the photocurrents show an opposite trend, resulting in the lowest dark current of 51.7 pA, highest photocurrent of 1.37 mA and highest PDCR value of 2.65 107 for sample S1. Therefore, a moderate hydrogen content can effectively improve the device performance. A comparison of the photoresponse parameters with previously reported Ga2O3-based UV PDs is demonstrated in figure 4. Our a-Ga2O3 PD (S1) shows an ultra-high PDCR and responsivity simultaneously, surpassing most of the ever-reported results.
Samples | Idark @ 5 V (A) | I254 @ 5 V (A) | I254/Idark @5 V | Responsivity@254 nm (A W-1) | EQE @254 nm | D@254 nm (Jones) |
S0 | 4.63 10-9 | 2.26 10-4 | 4.88 104 | 2.00 103 | 9.81 105% | 3.49 1013 |
S1 | 5.17 10-11 | 1.37 10-3 | 2.65 107 | 3.20 104 | 1.57 107% | 5.28 1015 |
S2 | 1.21 10-9 | 1.65 10-4 | 1.36 105 | 186.68 | 9.13 104% | 6.36 1012 |
S3 | 4.27 10-10 | 6.74 10-6 | 1.58 104 | 17.20 | 8.42 103% | 9.87 1011 |
To better understand the influence of hydrogen doping on the device performance, XPS measurement was carried out. Figure 5 shows the core level spectra of Ga 2p and O 1s after calibration with C 1s peak (284.8 eV). In figure 5(a), two shoulder peaks, locating at 1149.0 eV and 1122.2 eV, appear at the high-energy side of the original Ga 2p1/2 (1145.6 eV) and Ga 2p3/2 (1119.0 eV) after hydrogen doping. Besides, the height of the shoulder peaks first increases and then decreases against the hydrogen flux, leading to the maximum value in S1. As to the O 1s curves shown in figure 5(b), the peak position changes from 530.7 eV (S0) to 531.8 eV (S1) and then moves back to 531.0 eV for S2 and S3. As previously reported, a-Ga2O3 films grown in pure Ar environment often have a nonstoichiometric Ga/O ratio with more gallium dangling bonds than oxygen [5]. Despite of that, when a small amount of hydrogen (0.5 sccm) is introduced, these dangling bonds may be passivated by the formation of Ga-H and -OH couples, making the peak position of Ga 2p and O 1s move to the higher binding energy [40]. Consequently, electrons from the dangling gallium atoms will be trapped by Ga-H bonds, leading to a lower dark current than the undoped sample S0. As the hydrogen flux increases, the radical hydrogen atoms in the plasma tend to combine with each other to form H2 molecules and escape away from the films easily, making no contribution to or even weakening the passivation of the dangling Ga/O atoms. Consequently, the number of Ga-H and -OH bonds also decreases, leading to a decrease of the shoulder peaks of Ga 2p and recovery of O 1s. A schematic diagram of the chemical bonds under different hydrogen fluxes has been shown in figure 5(c).
Further, photoresponse behavior under ultra-weak UV light was investigated for sample S1. Figure 6(a) shows the I-V curves in dark and under illumination of the UV 254 nm light with different intensities. The PDCR value can reach two orders of magnitude under the irradiation of a 36 nW cm-2 light source. Under the weakest light source (<10 nW cm-2), the PDCR is still nearly an order of magnitude as shown in the inset of figure 6(a). Besides, the dependence of PDCR value on the applied bias voltage under the weakest light is displayed in figure 6(b). It can be seen that the PDCR increases as the voltage increases both at the positive and negative biases. The above results indicate the great potential of our UV PDs to be applied under extremely weak light sources.
At last, H-doped a-Ga2O3 UV PD was fabricated on PEN substrate using the same preparation condition as sample S1. This sample is named as P1. To investigate the flexibility of P1, I-V curves in dark and under UV 254 nm illumination were recorded in different bending states and after multiple bending cycles. As shown in figure 7(a), P1 exhibits almost the same photocurrent at different bending radius r (r = 8, 10 and 17 mm) as the flat state. However, the dark current fluctuates nearly one order of magnitude, probably due to the varying surface tensions and probe/electrode contacts under different bending states. Figure 7(b) compares the I-V curves in flat state before and after 10000 bending cycles with r = 10 mm. Both the dark and photocurrent degrade a little bit within the tolerable range. These results indicate the robustness of flexible a-Ga2O3 UV PD, promising the potential applications in flexible optoelectronic areas.
In summary, by precisely adjusting the flux of hydrogen gas during magnetron sputtering process, in situ H-doped a-Ga2O3 UV PDs with excellent performance have been developed both on the rigid quartz substrate and flexible PEN substrate. Based on the combined analysis with XRR, NR and XPS, it is suggested that the prevailing VO defects in a-Ga2O3 thin films have been effectively passivated via the formation of Ga-H bonds, resulting in an obvious reduction of the dark current. The optimum device shows a remarkable detection ability under ultra-weak UV light irradiation (<10 nW cm-2), implying its potential application in various fields such as civil and national security. In addition, flexible UV PD has been achieved with the superiority of low cost, room-temperature detection, easy integration and mass production, demonstrating great prospect in flexible and transparent electronic fields.
In this work, hydrogen-doped a-Ga2O3 thin films and the corresponding UV PDs have been achieved with a significant decrease of the dark current, providing a new way to improve the PDCR values of a-Ga2O3 UV PDs and endowing it the capability for ultra-weak light detection. In contrast to oxygen modulation, where the dark current and photocurrent decrease simultaneously as oxygen flux increases, a new defect may form after the incorporation of hydrogen atoms, which behaves like a killer of carriers under dark and a booster of carriers under light illumination. Although a series of measurements have been carried out, understanding of this new defects is still very limited since it is not easy to characterize a-Ga2O3 thin films with wide bandgap, high resistance and random atom arrangement, not to mention that detecting hydrogen is also a tough task. More brilliant characterization method as well as theoretical calculation of amorphous oxide semiconductors with hydrogen doping are definitely quite desirable. In addition, to promote the practical application of this device, the stability investigation must be executed further.
This work was supported by Guangdong Basic and Applied Basic Research Foundation (Grant Nos. 2022A1515110607 and 2019B1515120057), the National Natural Science Foundation of China (Grant Nos. 62174113, 12174275, 61874139, 61904201 and 11875088).
Authors to whom any correspondence should be addressed.
[1] |
Chen X, Ren F, Gu S, Ye J 2019 Review of gallium-oxide-based solar-blind ultraviolet photodetectors Photon. Res. 7 381 DOI: 10.1364/PRJ.7.000381
|
[2] |
Pearton S J, Yang J, Cary P H, Ren F, Kim J, Tadjer M J, Mastro M A 2018 A review of Ga2O3 materials, processing, and devices Appl. Phys. Rev. 5 011301 DOI: 10.1063/1.5006941
|
[3] |
Chen X, Ren F-F, Ye J, Gu S 2020 Gallium oxide-based solar-blind ultraviolet photodetectors Semicond. Sci. Technol. 35 023001 DOI: 10.1088/1361-6641/ab6102
|
[4] |
Liang H, Cui S, Su R, Guan P, He Y, Yang L, Chen L, Zhang Y, Mei Z, Du X 2019 Flexible x-ray detectors based on amorphous Ga2O3 thin films ACS Photonics 6 351-9 DOI: 10.1021/acsphotonics.8b00769
|
[5] |
Cui S, Mei Z, Zhang Y, Liang H, Du X 2017 Roomtemperature fabricated amorphous Ga2O3 highresponsespeed solarblind photodetector on rigid and flexible substrates Adv. Opt. Mater. 5 1700454 DOI: 10.1002/adom.201700454
|
[6] |
Zhou H, Zhang J, Zhang C, Feng Q, Zhao S, Ma P, Hao Y 2019 A review of the most recent progresses of state-of-art gallium oxide power devices J. Semicond. 40 011803 DOI: 10.1088/1674-4926/40/1/011803
|
[7] |
Zhang D, Du Z, Ma M, Zheng W, Liu S, Huang F 2019 Enhanced performance of solar-blind ultraviolet photodetector based on Mg-doped amorphous gallium oxide film Vacuum 159 204-8 DOI: 10.1016/j.vacuum.2018.10.025
|
[8] |
Qian L-X, Wu Z-H, Zhang Y-Y, Lai P T, Liu X-Z, Li Y-R 2017 Ultrahigh-responsivity, rapid-recovery, solar-blind photodetector based on highly nonstoichiometric amorphous gallium oxide ACS Photonics 4 2203-11 DOI: 10.1021/acsphotonics.7b00359
|
[9] |
Lorenz M R, Woods J F, Gambino R J 1967 Some electrical properties of the semiconductor -Ga2O3 J. Phys. Chem. Solids 28 403-4 DOI: 10.1016/0022-3697(67)90305-8
|
[10] |
Zhang Y-F, Chen X-H, Xu Y, Ren F-F, Gu S-L, Zhang R, Zheng Y-D, Ye J-D 2019 Transition of photoconductive and photovoltaic operation modes in amorphous Ga2O3-based solar-blind detectors tuned by oxygen vacancies Chin. Phys. B 28 028501 DOI: 10.1088/1674-1056/28/2/028501
|
[11] |
Liu L, Mei Z, Tang A, Azarov A, Kuznetsov A, Xue Q-K, Du X 2016 Oxygen vacancies: the origin of n-type conductivity in ZnO Phys. Rev. B 93 235305 DOI: 10.1103/PhysRevB.93.235305
|
[12] |
Han Z, Liang H, Huo W, Zhu X, Du X, Mei Z 2020 Boosted UV photodetection performance in chemically etched amorphous Ga2O3 thinfilm transistors Adv. Opt. Mater. 8 1901833 DOI: 10.1002/adom.201901833
|
[13] |
Qin Y, et al 2019 Amorphous gallium oxide-based gate-tunable high-performance thin film phototransistor for solar-blind imaging Adv. Electron. Mater. 5 1900389 DOI: 10.1002/aelm.201900389
|
[14] |
Tang H, Ishikawa K, Ide K, Hiramatsu H, Ueda S, Ohashi N, Kumomi H, Hosono H, Kamiya T 2015 Effects of residual hydrogen in sputtering atmosphere on structures and properties of amorphous In-Ga-Zn-O thin films J. Appl. Phys. 118 205703 DOI: 10.1063/1.4936552
|
[15] |
King P D C, Veal T D 2011 Conductivity in transparent oxide semiconductors J. Phys.: Condens. Matter 23 334214 DOI: 10.1088/0953-8984/23/33/334214
|
[16] |
McCluskey M D, Tarun M C, Teklemichael S T 2012 Hydrogen in oxide semiconductors J. Mater. Res. 27 2190-8 DOI: 10.1557/jmr.2012.137
|
[17] |
Varley J B, Weber J R, Janotti A, van de Walle C G 2010 Oxygen vacancies and donor impurities in -Ga2O3 Appl. Phys. Lett. 97 142106 DOI: 10.1063/1.3499306
|
[18] |
Varley J B, Peelaers H, Janotti A, van de Walle C G 2011 Hydrogenated cation vacancies in semiconducting oxides J. Phys.: Condens. Matter 23 334212 DOI: 10.1088/0953-8984/23/33/334212
|
[19] |
Qin Y, Stavola M, Fowler W B, Weiser P, Pearton S J 2019 Editors’ choicehydrogen centers in -Ga2O3: infrared spectroscopy and density functional theory ECS J. Solid State Sci. Technol. 8 Q3103 DOI: 10.1149/2.0221907jss
|
[20] |
de Jamblinne de Meux A, Pourtois G, Genoe J, Heremans P 2018 Defects in amorphous semiconductors: the case of amorphous indium gallium zinc oxide Phys. Rev. Appl. 9 054039 DOI: 10.1103/PhysRevApplied.9.054039
|
[21] |
Ide K, Nomura K, Hosono H, Kamiya T 2019 Electronic defects in amorphous oxide semiconductors: a review Phys. Status Solidi a 216 1800372 DOI: 10.1002/pssa.201800372
|
[22] |
Chen H, Zhan X, Liu X, Hai Y, Xu J, Zhu T, Yin W 2019 The behavior of helium atoms in He+ ion implanted W/Ni bilayer nanocomposite Appl. Surf. Sci. 486 274-80 DOI: 10.1016/j.apsusc.2019.05.007
|
[23] |
Li Q, et al 2019 Impact of donor-acceptor interaction and solvent additive on the vertical composition distribution of bulk heterojunction polymer solar cells ACS Appl. Mater. Interfaces 11 45979-90 DOI: 10.1021/acsami.9b15753
|
[24] |
Sears V F 1992 Neutron scattering lengths and cross sections Neutron News 3 26-37 DOI: 10.1080/10448639208218770
|
[25] |
Kang Y, Song H, Nahm H-H, Jeon S H, Cho Y, Han S 2014 Intrinsic nature of visible-light absorption in amorphous semiconducting oxides APL Mater. 2 032108 DOI: 10.1063/1.4868175
|
[26] |
Li Z, et al 2019 Flexible solar-blind Ga2O3 ultraviolet photodetectors with high responsivity and photo-to-dark current ratio IEEE Photon. J. 11 1-9 DOI: 10.1109/JPHOT.2019.2946731
|
[27] |
Li Z, et al 2019 Improving the production of high-performance solar-blind -Ga2O3 photodetectors by controlling the growth pressure J. Mater. Sci. 54 10335-45 DOI: 10.1007/s10853-019-03628-z
|
[28] |
Cui S-J, Mei Z-X, Hou Y-N, Chen Q-S, Liang H-L, Zhang Y-H, Huo W-X, Du X-L 2018 Enhanced photoresponse performance in Ga/Ga2O3 nanocomposite solar-blind ultraviolet photodetectors Chin. Phys. B 27 067301 DOI: 10.1088/1674-1056/27/6/067301
|
[29] |
Lee S H, Kim S B, Moon Y-J, Kim S M, Jung H J, Seo M S, Lee K M, Kim S-K, Lee S W 2017 High-responsivity deep-ultraviolet-selective photodetectors using ultrathin gallium oxide films ACS Photonics 4 2937-43 DOI: 10.1021/acsphotonics.7b01054
|
[30] |
Chen Y, Lu Y, Liao M, Tian Y, Liu Q, Gao C, Yang X, Shan C 2019 3D solarblind Ga2O3 photodetector array realized via origami method Adv. Funct. Mater. 29 1906040 DOI: 10.1002/adfm.201906040
|
[31] |
Lu Y, Krishna S, Tang X, Babatain W, Ben Hassine M, Liao C-H, Xiao N, Liu Z, Li X 2022 Ultrasensitive flexible -phase Ga2O3 solar-blind photodetector ACS Appl. Mater. Interfaces 14 34844-54 DOI: 10.1021/acsami.2c06550
|
[32] |
Wang Y, Xue Y, Su J, Lin Z, Zhang J, Chang J, Hao Y 2022 Realization of cost-effective and high-performance solar-blind ultraviolet photodetectors based on amorphous Ga2O3 prepared at room temperature Mater. Today Adv. 16 100324 DOI: 10.1016/j.mtadv.2022.100324
|
[33] |
Ji X, Yin X, Yuan Y, Yan S, Li X, Ding Z, Zhou X, Zhang J, Xin Q, Song A 2023 Amorphous Ga2O3 Schottky photodiodes with high-responsivity and photo-to-dark current ratio J. Alloys Compd. 933 167735 DOI: 10.1016/j.jallcom.2022.167735
|
[34] |
Sui Y, Liang H, Huo W, Wang Y, Mei Z 2020 A flexible and transparent -Ga2O3 solar-blind ultraviolet photodetector on mica J. Phys. D: Appl. Phys. 53 504001 DOI: 10.1088/1361-6463/abb1e7
|
[35] |
Wu C, Wu F, Ma C, Li S, Liu A, Yang X, Chen Y, Wang J, Guo D 2022 A general strategy to ultrasensitive Ga2O3 based self-powered solar-blind photodetectors Mater. Today Phys. 23 100643 DOI: 10.1016/j.mtphys.2022.100643
|
[36] |
Zhang C, et al 2023 High-performance fully transparent Ga2O3 solar-blind UV photodetector with the embedded indium-tin-oxide electrodes Mater. Today Phys. 33 101034 DOI: 10.1016/j.mtphys.2023.101034
|
[37] |
Zhu R, Liang H, Bai H, Zhu T, Mei Z 2022 Double is better: achieving an oxide solar-blind UV detector with ultrahigh detectivity and fast-refreshing capability Appl. Mater. Today 7 101556 DOI: 10.1016/j.apmt.2022.101556
|
[38] |
Hou X, et al 2022 Highperformance harsh-environment-resistant GaOX solar-blind photodetectors via defect and doping engineering Adv. Mater. 34 2106923 DOI: 10.1002/adma.202106923
|
[39] |
He H, Wu C, Hu H, Wang S, Zhang F, Guo D, Wu F 2023 Bandgap engineering and oxygen vacancy defect electroactivity inhibition in highly crystalline N-alloyed Ga2O3 films through plasma-enhanced technology J. Phys. Chem. Lett. 14 6444-50 DOI: 10.1021/acs.jpclett.3c01368
|
[40] |
Bang J, Matsuishi S, Hosono H 2017 Hydrogen anion and subgap states in amorphous In-Ga-Zn-O thin films for TFT applications Appl. Phys. Lett. 110 232105 DOI: 10.1063/1.4985627
|
1. | Yang, X., Wan, Y., Wang, Y. et al. Preparation, characterization and properties of B-doped β-Ga2O3 film. Journal of Alloys and Compounds, 2025. DOI:10.1016/j.jallcom.2025.179343 |
2. | Ma, Y., Deng, Z., Liang, H. et al. Wafer-Scale Fabrication of Broadband Sb2Se3 Photodetectors and their Multifunctional Optoelectronic Applications. Laser and Photonics Reviews, 2024, 18(12): 2400669. DOI:10.1002/lpor.202400669 |
3. | Wang, W., Wang, X., Yao, J. et al. Pulsed-Laser Deposition of Ge-Doped BiTe Nanofilms and Their Application in Room-Temperature Long-Wave Infrared Photodetection. Advanced Optical Materials, 2024, 12(28): 2401937. DOI:10.1002/adom.202401937 |
4. | Varshney, U., Sharma, A., Singh, P. et al. Revealing the photo-sensing capabilities of a super-flexible, paper-based wearable a-Ga2O3 self-driven ultra-high-performance solar-blind photodetector. Chemical Engineering Journal, 2024. DOI:10.1016/j.cej.2024.153910 |
Samples | Idark @ 5 V (A) | I254 @ 5 V (A) | I254/Idark @5 V | Responsivity@254 nm (A W-1) | EQE @254 nm | D@254 nm (Jones) |
S0 | 4.63 10-9 | 2.26 10-4 | 4.88 104 | 2.00 103 | 9.81 105% | 3.49 1013 |
S1 | 5.17 10-11 | 1.37 10-3 | 2.65 107 | 3.20 104 | 1.57 107% | 5.28 1015 |
S2 | 1.21 10-9 | 1.65 10-4 | 1.36 105 | 186.68 | 9.13 104% | 6.36 1012 |
S3 | 4.27 10-10 | 6.74 10-6 | 1.58 104 | 17.20 | 8.42 103% | 9.87 1011 |