摘要
β-Ga_(2)O_(3)作为第三代宽禁带半导体材料,具有禁带宽度大(4.9 eV)、击穿电场强,吸收边正好位于日盲紫外波段(波长200—280 nm)内,且在近紫外以及整个可见光波段具有较高的透过率,使得β-Ga_(2)O_(3)是一种非常适合制作日盲紫外光电探测器的材料.目前在p型β-Ga_(2)O_(3)材料方面的研究还较少,但p型β-Ga_(2)O_(3)材料的制备对于其光电器件的应用至关重要,因此成功制备p型β-Ga_(2)O_(3)材料就显得尤为关键.采用化学气相沉积法在蓝宝石衬底上生长出不同Cu掺杂量的β-Ga_(2)O_(3)薄膜,并对薄膜的形貌、晶体结构和光电特性进行了测试.发现随着Cu掺杂量的增加,样品(201)晶面的衍射峰向小角度方向发生了移动,这说明Cu2+替代了Ga3+进入到了Ga2O3晶格中.此外,在Cu掺杂β-Ga_(2)O_(3)薄膜上蒸镀Au作为叉指电极,制备出了金属-半导体-金属结构光电导型日盲紫外探测器,并对其紫外探测性能进行了研究.结果表明,在10 V偏压、254 nm波长紫外光下,器件的光暗电流比约为3.81×102,器件的上升时间和下降时间分别是0.11 s和0.13 s.此外,在光功率密度为64μW/cm2时,器件的响应度和外部量子效率分别是1.72 A/W和841%.
Solar-blind UV photodetectors(SBPs)have attracted great attention because they are widely used in missile tracking,fire detection,biochemical analysis,astronomical observations,space-to-space communications,etc.At present,it is found that wide bandgap semiconductor materials such as Al_(x)Ga_(1-x)N,Mg_(1)Zn_(1-x)O,diamond andβ-Ga_(2)O_(3)are ideal semiconductor materials for developing high-performance SBPs.The ultra-wide band gap semiconductor material,β-Ga_(2)O_(3),has a large band gap width of 4.9 eV,strong breakdown electric field,absorption edge located in the solar blind ultraviolet band(200−280 nm),and it also has high transmittance in the near ultraviolet and the whole visible band.Therefore,β-Ga_(2)O_(3)is a very suitable material for making solar blind UV photodetectors.However,the p-typeβ-Ga_(2)O_(3)is difficult to dope,which limits the further development ofβ-Ga_(2)O_(3)devices.In this work,theβ-Ga_(2)O_(3)thin films with different Cu doping content are grown on sapphire substrates by chemical vapor deposition method,and the morphology,crystal structure and optical properties ofβ-Ga_(2)O_(3)films are measured.The test results show that the surfaces ofβ-Ga_(2)O_(3)films with different Cu content are relatively smooth,and the()diffraction peak positions shift toward the lower degree side with the increase of Cu content,which indicates that Cu^(2+)replaces Ga^(3+)and enters into the b-Ga2O3 lattice.The optical absorption spectrum measurement indicates that the energy gaps of samples are evidently narrowed with the increase of Cu doping concentration.Hall measurements indicate that the Cu dopedβ-Ga_(2)O_(3)thin films have a p-type conductivity with a hole concentration of 7.36×10^(14),4.83×10^(15) and 1.69×10^(16) cm^(−3),respectively.In addition,a photoconductive UV detector with metal-semiconductor-metal structure is prepared by evaporating Au on a Cu-dopedβ-Ga_(2)O_(3)thin film,and its UV detection performance is studied.The results show that the photocurrent value of the device increases with Cu content increasing.The photo-to-dark current ratio(Il/Id)is about 3.8×10^(2) of 2.4%Cu content device under 254 nm-wavelength light at 10 V.The rise time and decay time are 0.11 s and 0.13 s,respectively.Furthermore,the responsivity and external quantum efficiency can reach 1.72 A/W and 841%under 254 nm-wavelength light with a light intensity of 64μW/cm2.
作者
刘玮
冯秋菊
†宜子琪
俞琛
王硕
王彦明
隋雪
梁红伟
Liu Wei;Feng Qiu-Ju;Yi Zi-Qi;Yu Chen;Wang Shuo;Wang Yan-Ming;Sui Xue;Liang Hong-Wei(School of Physics and Electronic Technology,Liaoning Normal University,Dalian 116029,China;School of Microelectronics,Dalian University of Technology,Dalian 116024,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第19期292-298,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:12075045)
辽宁省自然科学基金(批准号:2020-MS-243)
大连市科技创新基金项目(批准号:2022JJ12GX023)
辽宁师范大学2022年高端科研成果培育资助计划(批准号:22GDL002)资助的课题。
