Interface regulation and photoelectric performance of CdZnTe/AlN composite structure for UV photodetector

Abstract

AlN ceramic substrates (c-AlN), with excellent thermal conductivity, were used to deposit high-quality polycrystalline CdZnTe (CZT) thick films for the first time. Meanwhile, AlN transition layers, made by magnetron sputtering method, have been introduced and annealed to modulate the interface properties of CZT/c-AlN composite structures for UV photodetectors. The relationship between the structure as well as performance of CZT films and the anneal temperature of AlN transition layers was studied by SEM, XRD, EDS, UV–vis spectra, XPS and current–voltage (I-V) characteristic. The CZT films deposited on the AlN transition layer annealed at 1200 °C have the best properties, with the full width at half maximum (FWHM) and leakage current of 0.163°and 2.15 × 10−9 A, respectively. The interface regulation can effectively promote the crystallinity of CZT films and lead to optimum UV detection performance of CZT/AlN composite structures.