Fabrication of stable metal halide perovskite nanowire arrays for optoelectronic devices (Conference Presentation)

Abstract

Metal halide perovskite materials are emerging as highly promising materials for high performance optoelectronic devices thus triggered broad attention. Nanostructured perovskite materials have wide applications in nanoelectronics and nano-optoelectronics. Due to incompatibility of metal halide perovskite materials with conventional lithography techniques, it is preferable to achieve nano-perovskite material growth and assembly at the same time for further device applications. In our work, we have developed a chemical vapor deposition (CVD) process to grow ordered three-dimensional (3-D) metal halide nanowire (NW) arrays in nanoengineering templates. This unique CVD process utilizes metal nanoclusters at the bottom of vertical nanochannels to initiate high quality NW growth. As the nanochannels have largely controllable geometrical factors, namely, periodicity, diameter and depth, NW geometry can also be precisely nanoengineered. As the result, the ordered 3-D NW arrays can achieve ultra-high NW density in the range of ~109/cm2. The 3-D NW arrays are conspicuously promising for 3-D integrated nano-electronics/optoelectronics. To further demonstrate the technological potency of the perovskite NW arrays, they have been fabricated into photodetectors and proof-of-concept image sensors. Each image sensor consists of 1,024 photodiode pixels made of vertical perovskite NWs, and the imaging functionality has been verified by recognizing various optical patterns projected on the sensor. In addition, we have also discovered that the chemically and mechanically robust template can effectively protect perovskite NWs from water and oxygen invasion thus the material stability is significantly better than planar perovskite films confirmed by photoluminescence and photoelectric measurements.