Department of Physics, Texas State University , San Marcos, Texas 78666, United States.
Energy Efficiency Center, National University of Science and Technology, MISiS , Moscow 119049, Russia.
ACS Nano. 2016 Dec 27;10(12):10921-10928. doi: 10.1021/acsnano.6b05535. Epub 2016 Nov 18.
Recently, organolead halide-based perovskites have emerged as promising materials for optoelectronic applications, particularly for photovoltaics, photodetectors, and lasing, with low cost and high performance. Meanwhile, nanoscale photodetectors have attracted tremendous attention toward realizing miniaturized optoelectronic systems, as they offer high sensitivity, ultrafast response, and the capability to detect beyond the diffraction limit. Here we report high-performance nanoscale-patterned perovskite photodetectors implemented by nanoimprint lithography (NIL). The spin-coated lead methylammonium triiodide perovskite shows improved crystallinity and optical properties after NIL. The nanoimprinted metal-semiconductor-metal photodetectors demonstrate significantly improved performance compared to the nonimprinted conventional thin-film devices. The effects of NIL pattern geometries on the optoelectronic characteristics were studied, and the nanograting pattern based photodetectors demonstrated the best performance, showing approximately 35 times improvement on responsivity and 7 times improvement on on/off ratio compared with the nonimprinted devices. The high performance of NIL-nanograting photodetectors likely results from high crystallinity and favored nanostructure morphology, which contribute to higher mobility, longer diffusion length, and better photon absorption. Our results have demonstrated that the NIL is a cost-effective method to fabricate high-performance perovskite nanoscale optoelectronic devices, which may be suitable for manufacturing of high-density perovskite nanophotodetector arrays and to provide integration with state-of-the-art electronic circuits.
最近，基于有机卤化铅的钙钛矿已成为光电应用的有前途的材料，特别是在光伏、光电探测器和激光领域，具有低成本和高性能的优势。同时，纳米级光电探测器因其高灵敏度、超快响应和超越衍射极限的探测能力，吸引了人们对实现小型化光电系统的极大关注。在这里，我们报告了通过纳米压印光刻（NIL）实现的高性能纳米图案钙钛矿光电探测器。经过 NIL 处理后，旋涂的铅甲脒碘化铅钙钛矿显示出改善的结晶度和光学性能。与非压印的传统薄膜器件相比，纳米压印的金属-半导体-金属光电探测器表现出显著改善的性能。研究了 NIL 图案几何形状对光电特性的影响，基于纳米光栅图案的光电探测器表现出最佳性能，与非压印器件相比，响应率提高了约 35 倍，开关比提高了 7 倍。NIL-纳米光栅光电探测器的高性能可能归因于高结晶度和有利的纳米结构形态，这有助于提高迁移率、延长扩散长度和更好地吸收光子。我们的结果表明，NIL 是制造高性能钙钛矿纳米级光电设备的一种具有成本效益的方法，它可能适用于高密度钙钛矿纳米光电探测器阵列的制造，并与最先进的电子电路集成。
