Flexible electronic devices have attracted much attention due to their practical and commercial value. Integration of thin films with soft substrate is an effective way to fabricate flexible electronic devices. Ga_2O_...Flexible electronic devices have attracted much attention due to their practical and commercial value. Integration of thin films with soft substrate is an effective way to fabricate flexible electronic devices. Ga_2O_3 thin films deposited directly on soft substrates would be amorphous mostly. However, the thickness of the thin film obtained by mechanical exfoliation method is difficult to control and the edge of the film is fragile and easy to be damaged. In this work, we fabricated free-standing Ga_2O_3 thin films using the water-soluble perovskite Sr_3Al_2O_6 as a sacrificial buffer layer. The obtained Ga_2O_3 thin films were polycrystalline. The thickness and dimension of the films were controllable. A flexible Ga_2O_3solar-blind UV photodetector was fabricated by transferring the free-standing Ga_2O_3 film on a flexible polyethylene terephthalate substrate. The results displayed that the photoelectric performances of the flexible Ga_2O_3 photodetector were not sensitive to bending of the device. The free-standing Ga_2O_3 thin films synthesized through the method described here can be transferred to any substrates or integrated with other thin films to fabricate electronic devices.展开更多
Gallium oxide(Ga_2O_3), a typical ultra wide bandgap semiconductor, with a bandgap of ~4.9 e V, critical breakdown field of 8 MV/cm, and Baliga's figure of merit of 3444, is promising to be used in high-power and ...Gallium oxide(Ga_2O_3), a typical ultra wide bandgap semiconductor, with a bandgap of ~4.9 e V, critical breakdown field of 8 MV/cm, and Baliga's figure of merit of 3444, is promising to be used in high-power and high-voltage devices.Recently, a keen interest in employing Ga_2O_3 in power devices has been aroused. Many researches have verified that Ga_2O_3 is an ideal candidate for fabricating power devices. In this review, we summarized the recent progress of field-effect transistors(FETs) and Schottky barrier diodes(SBDs) based on Ga_2O_3, which may provide a guideline for Ga_2O_3 to be preferably used in power devices fabrication.展开更多
The symmetric Ti/Au bi-layer point electrodes have been successfully patterned on theβ-Ga;O;films which are prepared by metal–organic chemical vapor deposition(MOCVD)and theγ-Cu I films which are prepared by spin-c...The symmetric Ti/Au bi-layer point electrodes have been successfully patterned on theβ-Ga;O;films which are prepared by metal–organic chemical vapor deposition(MOCVD)and theγ-Cu I films which are prepared by spin-coating.The fabricated heterojunction has a large open circuit voltage(Voc)of 0.69 V,desired for achieving self-powered operation of a photodetector.Irradiated by 254-nm ultraviolet(UV)light,when the bias voltage is-5 V,the dark current(Idark)of the device is 0.47 p A,the photocurrent(Iphoto)is-50.93 n A,and the photo-to-dark current ratio(Iphoto/Idark)reaches about 1.08×10;.The device has a stable and fast response speed in different wavelengths,the rise time(τr)and decay time(τd)are 0.762 s and 1.741 s under 254-nm UV light illumination,respectively.While theτr andτd are 10.709 s and7.241 s under 365-nm UV light illumination,respectively.The time-dependent(I–t)response(photocurrent in the order of10-10 A)can be clearly distinguished at a small light intensity of 1μW·cm;.The internal physical mechanism affecting the device performances is discussed by the band diagram and charge carrier transfer theory.展开更多
Si-dopedβ-Ga_(2)O_(3)films are fabricated through metal-organic chemical vapor deposition(MOCVD).Solar-blind ultraviolet(UV)photodetector(PD)based on the films is fabricated by standard photolithography,and the photo...Si-dopedβ-Ga_(2)O_(3)films are fabricated through metal-organic chemical vapor deposition(MOCVD).Solar-blind ultraviolet(UV)photodetector(PD)based on the films is fabricated by standard photolithography,and the photodetection properties are investigated.The results show that the photocurrent increases to 11.2 mA under 200μW·cm^(-2)254 nm illumination and±20 V bias,leading to photo-responsivity as high as 788 A·W^(-1).The Si-dopedβ-Ga2O3-based PD is promised to perform solar-blind photodetection with high performance.展开更多
We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky photodiodes.The device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 V.In addition,the photodiode detecto...We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky photodiodes.The device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 V.In addition,the photodiode detector shows a dark current of 0.3 pA,a photo-responsivity(R) of 2.875 mA/W,a special detectivity(D*) of 10^(10) Jones,and an external quantum efficiency(EQE) of 1.4% at zero bias,illustrating a self-powered operation.This work may advance the development of the Ga_(2)O_(3)-based Schottky diode solar-blind photodetectors.展开更多
Can the modulation effect of charge-carrier transfer be inherited from a single layer to its heterojunction structure?Certainly,the answer is yes.Herein,we experimentally verify that the photodetection performance mod...Can the modulation effect of charge-carrier transfer be inherited from a single layer to its heterojunction structure?Certainly,the answer is yes.Herein,we experimentally verify that the photodetection performance modulation effect of oxygen vacancy(Vo)is transmitted from theε-Ga_(2)O_(3)layer to the PEDOT:PSS/ε-Ga_(2)O_(3)(PGO)hybrid heterojunction.By adopting the annealedε-Ga_(2)O_(3)films,whose Voconcentrations are remolded by annealing ambients,the constructed PGO photodetectors(PDs)demonstrate regulable self-powered performance.As the V_(o)defects decrease,the photodetection properties are effectively enhanced with a high photo-to-dark current ratio of 2.37×10^(7),an excellent on/off switching ratio of 6.45×10^(5),fast rise/decay time of 121/72 ms,a large responsivity of 67.9 m A/W,superior detectivity of 9.2×10^(13)Jones,an outstanding external quantum efficiency of 33.2%,and a high rejection ratio(R_(250)/R_(400))of 5.96×10^(6)at 0 V in PGO-O;PD.The better photoresponse is attributed to the less V_(o)defect concentration in theε-Ga_(2)O_(3)layer,which could favor the lower electron-trapping probability and a more efficient charge-carrier transfer.Considering the universality of V_(o)defects in oxide materials,the proposed regulation strategy of photoresponse will open the route of high self-powered performance for next-generation ultraviolet PDs.展开更多
The low dark current, high responsivity and high specific detectivity could be preferably achieved in detectors based on junctions, owing to the efficient constraint of carriers. Compared with the other junctions, pla...The low dark current, high responsivity and high specific detectivity could be preferably achieved in detectors based on junctions, owing to the efficient constraint of carriers. Compared with the other junctions, planar Schottky junctions have simple structures and technological demands and are easy integrated. Herein, in this work, we prepared the β-Ga_(2)O_(3) thin film by metalorganic chemical vapor deposition method to construct planar Ti/β-Ga2O3/Ni Schottky photodiode detectors with different onstate resistances. Fortunately, all the devices exhibit state-of-the-art performances, such as responsivity of 175–1372 A W^(-1),specific detectivity of 10^(14) Jones and external quantum efficiency of 85700%–671500%. In addition, the dependences of device performances on the on-state resistances indicate that the higher dark currents, photocurrents and photoresponsivities may well be obtained when on-state resistance is smaller, due to the less external power is used to overcome the impendence and condensance at the Ti/β-Ga_(2)O_(3) and Ni/β-Ga_(2)O_(3) interfaces, but contributing to higher electric current flow both in the dark and under illuminations.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51572033,51572241,61774019,61704153,and 11404029)the Fund of State Key Laboratory of IPOC(BUPT)+1 种基金the Open Fund of IPOC(BUPT)Beijing Municipal Commission of Science and Technology,China(Grant No.SX2018-04)
文摘Flexible electronic devices have attracted much attention due to their practical and commercial value. Integration of thin films with soft substrate is an effective way to fabricate flexible electronic devices. Ga_2O_3 thin films deposited directly on soft substrates would be amorphous mostly. However, the thickness of the thin film obtained by mechanical exfoliation method is difficult to control and the edge of the film is fragile and easy to be damaged. In this work, we fabricated free-standing Ga_2O_3 thin films using the water-soluble perovskite Sr_3Al_2O_6 as a sacrificial buffer layer. The obtained Ga_2O_3 thin films were polycrystalline. The thickness and dimension of the films were controllable. A flexible Ga_2O_3solar-blind UV photodetector was fabricated by transferring the free-standing Ga_2O_3 film on a flexible polyethylene terephthalate substrate. The results displayed that the photoelectric performances of the flexible Ga_2O_3 photodetector were not sensitive to bending of the device. The free-standing Ga_2O_3 thin films synthesized through the method described here can be transferred to any substrates or integrated with other thin films to fabricate electronic devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61774019,51572033,and 51572241)the Beijing Municipal Commission of Science and Technology,China(Grant No.SX2018-04)
文摘Gallium oxide(Ga_2O_3), a typical ultra wide bandgap semiconductor, with a bandgap of ~4.9 e V, critical breakdown field of 8 MV/cm, and Baliga's figure of merit of 3444, is promising to be used in high-power and high-voltage devices.Recently, a keen interest in employing Ga_2O_3 in power devices has been aroused. Many researches have verified that Ga_2O_3 is an ideal candidate for fabricating power devices. In this review, we summarized the recent progress of field-effect transistors(FETs) and Schottky barrier diodes(SBDs) based on Ga_2O_3, which may provide a guideline for Ga_2O_3 to be preferably used in power devices fabrication.
基金supported by the National Natural Science Foundation of China(Grunt No.61774019)。
文摘The symmetric Ti/Au bi-layer point electrodes have been successfully patterned on theβ-Ga;O;films which are prepared by metal–organic chemical vapor deposition(MOCVD)and theγ-Cu I films which are prepared by spin-coating.The fabricated heterojunction has a large open circuit voltage(Voc)of 0.69 V,desired for achieving self-powered operation of a photodetector.Irradiated by 254-nm ultraviolet(UV)light,when the bias voltage is-5 V,the dark current(Idark)of the device is 0.47 p A,the photocurrent(Iphoto)is-50.93 n A,and the photo-to-dark current ratio(Iphoto/Idark)reaches about 1.08×10;.The device has a stable and fast response speed in different wavelengths,the rise time(τr)and decay time(τd)are 0.762 s and 1.741 s under 254-nm UV light illumination,respectively.While theτr andτd are 10.709 s and7.241 s under 365-nm UV light illumination,respectively.The time-dependent(I–t)response(photocurrent in the order of10-10 A)can be clearly distinguished at a small light intensity of 1μW·cm;.The internal physical mechanism affecting the device performances is discussed by the band diagram and charge carrier transfer theory.
基金the National Natural Science Foundation of China(Grant Nos.61774019 and 51572033)the Fund of State Key Laboratory of Information Photonics and Optical Communications(BUPT)the Fundamental Research Funds for the Central Universities,China.
文摘Si-dopedβ-Ga_(2)O_(3)films are fabricated through metal-organic chemical vapor deposition(MOCVD).Solar-blind ultraviolet(UV)photodetector(PD)based on the films is fabricated by standard photolithography,and the photodetection properties are investigated.The results show that the photocurrent increases to 11.2 mA under 200μW·cm^(-2)254 nm illumination and±20 V bias,leading to photo-responsivity as high as 788 A·W^(-1).The Si-dopedβ-Ga2O3-based PD is promised to perform solar-blind photodetection with high performance.
基金Project supported by BUPT Excellent Ph.D.Students Foundation(Grant No.CX2020314)the National Natural Science Foundation of China(Grant Nos.61774019,51572033,and 51572241)+1 种基金the Fund of State Key Laboratory of Information Photonics and Optical Communications(BUPT)the Fundamental Research Funds for the Central Universities,China。
文摘We report the edge-defined-film-fed(EFG)-grown β-Ga_(2)O_(3)-based Schottky photodiodes.The device has a reverse leakage current of ~nA and a rectified ratio of ~10^(4) at ±5 V.In addition,the photodiode detector shows a dark current of 0.3 pA,a photo-responsivity(R) of 2.875 mA/W,a special detectivity(D*) of 10^(10) Jones,and an external quantum efficiency(EQE) of 1.4% at zero bias,illustrating a self-powered operation.This work may advance the development of the Ga_(2)O_(3)-based Schottky diode solar-blind photodetectors.
基金supported by the National Natural Science Foundation of China(Grant Nos.61774019,61704153)。
文摘Can the modulation effect of charge-carrier transfer be inherited from a single layer to its heterojunction structure?Certainly,the answer is yes.Herein,we experimentally verify that the photodetection performance modulation effect of oxygen vacancy(Vo)is transmitted from theε-Ga_(2)O_(3)layer to the PEDOT:PSS/ε-Ga_(2)O_(3)(PGO)hybrid heterojunction.By adopting the annealedε-Ga_(2)O_(3)films,whose Voconcentrations are remolded by annealing ambients,the constructed PGO photodetectors(PDs)demonstrate regulable self-powered performance.As the V_(o)defects decrease,the photodetection properties are effectively enhanced with a high photo-to-dark current ratio of 2.37×10^(7),an excellent on/off switching ratio of 6.45×10^(5),fast rise/decay time of 121/72 ms,a large responsivity of 67.9 m A/W,superior detectivity of 9.2×10^(13)Jones,an outstanding external quantum efficiency of 33.2%,and a high rejection ratio(R_(250)/R_(400))of 5.96×10^(6)at 0 V in PGO-O;PD.The better photoresponse is attributed to the less V_(o)defect concentration in theε-Ga_(2)O_(3)layer,which could favor the lower electron-trapping probability and a more efficient charge-carrier transfer.Considering the universality of V_(o)defects in oxide materials,the proposed regulation strategy of photoresponse will open the route of high self-powered performance for next-generation ultraviolet PDs.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61774019,51572033 and 51572241)the Fund of State Key Laboratory of Information Photonics and Optical Communications(BUPT)+1 种基金the Fundamental Research Funds for the Central UniversitiesBUPT Excellent Ph D Students Foundation (Grant No. CX2020314)。
文摘The low dark current, high responsivity and high specific detectivity could be preferably achieved in detectors based on junctions, owing to the efficient constraint of carriers. Compared with the other junctions, planar Schottky junctions have simple structures and technological demands and are easy integrated. Herein, in this work, we prepared the β-Ga_(2)O_(3) thin film by metalorganic chemical vapor deposition method to construct planar Ti/β-Ga2O3/Ni Schottky photodiode detectors with different onstate resistances. Fortunately, all the devices exhibit state-of-the-art performances, such as responsivity of 175–1372 A W^(-1),specific detectivity of 10^(14) Jones and external quantum efficiency of 85700%–671500%. In addition, the dependences of device performances on the on-state resistances indicate that the higher dark currents, photocurrents and photoresponsivities may well be obtained when on-state resistance is smaller, due to the less external power is used to overcome the impendence and condensance at the Ti/β-Ga_(2)O_(3) and Ni/β-Ga_(2)O_(3) interfaces, but contributing to higher electric current flow both in the dark and under illuminations.