The metal-semiconductor-metal (MSM) structure is a popular architecture for developing Ga
2
O
3
solar blind photodetectors. The nature of metal-semiconductor contact is decisive for the operation mode, gain mechanism and device performances. In this contribution,
κ
-Ga
2
O
3
MSM solar-blind photodetectors with Ti/Ga
2
O
3
Ohmic and Ni/Ga
2
O
3
Schottky contacts were constructed on the high-quality Si-doped
κ
-Ga
2
O
3
epilayer grown by hydride vapor phase epitaxy. The Ti/
κ
-Ga
2
O
3
/Ti Ohmic MSM device is operated in a photoconductive mode, exhibiting a maximum responsivity of 322.5 A W
−1
and a high rejection ratio of over 10
5
, but with an undesirable sub-gap response and high dark current. In comparison, the Ni/Ga
2
O
3
/Ni photodiode with a back-to-back Schottky configuration is operated in a mixed photovoltaic and photoconductive mode, demonstrating a decent photoresponsivity of 0.37 A W
−1
, a maintained high rejection ratio of 1.16 × 10
5
, a detectivity of 3.51 × 10
13
Jones and the elimination of slow photoresponse from sub-gap states. The frequency-dependent photoresponse and transient photocurrent characteristics indicate that the persistent photoconductivity effect is responsible for the high gain achieved in the Ti/Ga
2
O
3
/Ti photoconductor, and the dominant slow transient decay component is a fingerprint of photoexcited carrier trapping and repopulation. The response speed is improved in the Ni/Ga
2
O
3
/Ni Schottky MSM device, whereas carrier transport across interdigitated fingers is affected by bulk traps, limiting the overall response-bandwidth merit.
中文翻译：
金属-半导体-金属 (MSM) 结构是用于开发 Ga
2
O
3 日
盲光电探测器的流行架构。金属-半导体接触的性质决定了工作模式、增益机制和器件性能。在这个贡献中，
κ
-具有 Ti/Ga 2
O
3
欧姆和 Ni/Ga
2
O
3
肖特基触点的Ga
2
O
3
MSM 日盲光电探测器构建在高质量的硅掺杂材料上
κ
-通过氢化物气相外延生长的Ga
2
O
3外延层。
钛/
κ
-Ga
2
O
3
/Ti Ohmic MSM 器件以光电导模式运行，表现出 322.5 AW
-1的最大响应度和超过 10
5
的高抑制比，但具有不希望的子带隙响应和高暗电流。相比之下，具有背靠背肖特基配置的 Ni/Ga
2
O
3 /Ni 光电二极管以混合光伏和光电导模式运行，表现出 0.37 AW
-1
的良好光响应性，保持 1.16 × 的高抑制比10
5
，检测灵敏度为3.51×10
13
琼斯和从子间隙状态消除慢光响应。频率相关的光响应和瞬态光电流特性表明，持续的光电导效应是 Ti/Ga
2
O
3
/Ti 光电导体实现高增益的原因，而主要的慢速瞬态衰减分量是光激发载流子捕获和再填充的指纹.
Ni/Ga 2
O
3
/Ni 肖特基 MSM 器件的响应速度得到提高，而叉指间的载流子传输受到体陷阱的影响，从而限制了整体响应带宽的优点。
