Yao Xiaomei, Zhang Xutao, Kang Tingting, Song Zhiyong, Sun Qiang, Wei Dongdong, Zou Jin, Chen Pingping
State Key Laboratory of Infrared Physics, Shanghai Institute of Technical Physics Chinese Academy of Sciences, Shanghai, 200083, China.
University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China.
Nanoscale Res Lett. 2021 Jan 21;16(1):13. doi: 10.1186/s11671-021-03476-4.
A simple fabrication of end-bonded contacts InAsSb NW (nanowire) array detector to weak light is demonstrated in this study. The detector is fabricated using InAsSb NW array grown by molecular beam epitaxy on GaAs substrate. The metal-induced gap states are induced by the end-bonded contact which suppresses the dark current at various temperatures. The existence of the interface dipole due to the interfacial gap states enhances the light excitation around the local field and thus upgrades the photoresponsivity and photodetectivity to the weak light. The light intensity of the infrared light source in this report is 14 nW/cm which is about 3 to 4 orders of magnitude less than the laser source. The responsivity of the detector has reached 28.57 A/W at room temperature with the light (945 nm) radiation, while the detectivity is 4.81 × 10 cm·Hz W. Anomalous temperature-dependent performance emerges at the variable temperature experiments, and we discussed the detailed mechanism behind the nonlinear relationship between the photoresponse of the device and temperatures. Besides, the optoelectronic characteristics of the detector clarified that the light-trapping effect and photogating effect of the NWs can enhance the photoresponse to the weak light across ultraviolet to near-infrared. These results highlight the feasibility of the InAsSb NW array detector to the infrared weak light without a cooling system.
本研究展示了一种用于弱光探测的端接式接触InAsSb纳米线（NW）阵列探测器的简易制造方法。该探测器是利用分子束外延在GaAs衬底上生长的InAsSb NW阵列制造而成。端接式接触会诱导金属诱导能隙态，从而在不同温度下抑制暗电流。由于界面能隙态导致的界面偶极子的存在增强了局部场周围的光激发，进而提升了对弱光的光响应度和光探测率。本报告中红外光源的光强为14 nW/cm，比激光源低约3至4个数量级。在室温下，探测器对945 nm光辐射的响应度达到了28.57 A/W，而探测率为4.81×10 cm·Hz W。在变温实验中出现了异常的温度依赖性性能，我们讨论了该器件光响应与温度之间非线性关系背后的详细机制。此外，探测器的光电特性表明，NWs的光捕获效应和光门效应可以增强对从紫外到近红外的弱光的光响应。这些结果突出了InAsSb NW阵列探测器在无需冷却系统的情况下探测红外弱光的可行性。
