Lin Sheng, Lin Tingjun, Wang Wenliang, Liu Chao, Ding Yao
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Department of Electronic Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Materials (Basel). 2023 Jun 24;16(13):4569. doi: 10.3390/ma16134569.
Photodetectors (PDs) based on two-dimensional (2D) materials have promising applications in modern electronics and optoelectronics. However, due to the intralayer recombination of the photogenerated carriers and the inevitable surface trapping stages of the constituent layers, the PDs based on 2D materials usually suffer from low responsivity and poor response speed. In this work, a distinguished GaN-based photodetector is constructed on a sapphire substrate with Te/metal electrodes. Due to the metal-like properties of tellurium, the band bending at the interface between Te and GaN generates an inherent electric field, which greatly reduces the carrier transport barrier and promotes the photoresponse of GaN. This Te-enhanced GaN-based PD show a promising responsivity of 4951 mA/W, detectivity of 1.79 × 10 Jones, and an external quantum efficiency of 169%. In addition, owing to the collection efficiency of carriers by this Te-GaN interface, the response time is greatly decreased compared with pure GaN PDs. This high performance can be attributed to the fact that Te reduces the contact resistance of the metal electrode Au/Ti to GaN, forming an ohmic-like contact and promoting the photoresponse of GaN. This work greatly extends the application potential of GaN in the field of high-performance photodetectors and puts forward a new way of developing high performance photodetectors.
基于二维（2D）材料的光电探测器（PD）在现代电子学和光电子学中具有广阔的应用前景。然而，由于光生载流子的层内复合以及组成层不可避免的表面俘获阶段，基于二维材料的光电探测器通常响应度较低且响应速度较差。在这项工作中，在具有碲/金属电极的蓝宝石衬底上构建了一种卓越的氮化镓基光电探测器。由于碲具有类似金属的特性，碲与氮化镓界面处的能带弯曲会产生一个固有电场，这大大降低了载流子传输势垒并促进了氮化镓的光响应。这种碲增强的氮化镓基光电探测器展现出4951 mA/W的可观响应度、1.79×10琼斯的探测率以及169%的外量子效率。此外，由于这种碲 - 氮化镓界面的载流子收集效率，与纯氮化镓光电探测器相比，响应时间大大缩短。这种高性能可归因于碲降低了金属电极金/钛与氮化镓的接触电阻，形成了类似欧姆接触并促进了氮化镓的光响应。这项工作极大地扩展了氮化镓在高性能光电探测器领域的应用潜力，并提出了一种开发高性能光电探测器的新方法。
