title: Nanoimprinted Perovskite Nanograting Photodetector with Improved Efficiency.
abstract: 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.
authors.forename: Honglei
authors.identifier: 0000-0002-5079-625X
authors.initials: H
authors.lastname: Wang
authors.forename: Ross
authors.initials: R
authors.lastname: Haroldson
authors.forename: Balasubramaniam
authors.initials: B
authors.lastname: Balachandran
authors.affiliation: Department of Physics, Texas State University , San Marcos, Texas 78666, United States.
authors.forename: Alex
authors.initials: A
authors.lastname: Zakhidov
authors.affiliation: Department of Physics, Texas State University , San Marcos, Texas 78666, United States.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Sohal
authors.forename: Julia Y
authors.identifier: 0000-0003-4434-2160
authors.initials: JY
authors.lastname: Chan
authors.affiliation: Energy Efficiency Center, National University of Science and Technology, MISiS , Moscow 119049, Russia.
authors.forename: Anvar
authors.initials: A
authors.lastname: Zakhidov
authors.affiliation: ASIC and System State-Key Laboratory, Institute of Microelectronics, Fudan University , Shanghai 200433, China.
authors.forename: Walter
authors.initials: W
authors.lastname: Hu
keywords: crystallinity; nanogratings; nanoimprint lithography; nanoscale; perovskite; photodetector