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GeTe is an important narrow bandgap semiconductor material and has found application in the fields of phase change storage as well as spintronics devices. However, it has not been studied for application in the field of infrared photovoltaic detectors working at room temperature. Herein, GeTe nanofilms were grown by magnetron sputtering technique and characterized to investigate its physical, electrical, and optical properties. A high-performance infrared photovoltaic detector based on GeTe/Si heterojunction with the detectivity of 8 × 10 11 Jones at 850 nm light irradiation at room temperature was demonstrated.

Ultraviolet (UV) photodetector has attracted extensive interests due to its wide-ranging applications from defense technology to optical communications. The use of wide bandgap metal oxide semiconductor materials is of great interest in the development of UV photodetector due to their unique electronic and optical properties. In this work, deep UV photodetector based on NiO/β-Ga 2 O 3 heterojunction was developed and investigated. The β-Ga 2 O 3 layer was prepared by magnetron sputtering and exhibited selective orientation along the family of ([Formula: see text] 01) crystal plane after annealing. The photodetector demonstrated good performance with a high responsivity (R) of 27.43 AW -1 under a 245-nm illumination (27 μWcm -2 ) and the maximum detectivity (D*) of 3.14 × 10 12  cmHz 1/2  W -1 , which was attributed to the p-NiO/n-β-Ga 2 O 3 heterojunction.

Tantalum disulfide (TaS 2 ) two-dimensional film material has attracted wide attention due to its unique optical and electrical properties. In this work, we report the preparation of 1 T-TaS 2 quantum dots (1 T-TaS 2 QDs) by top-down method. Herein, we prepared the TaS 2 QDs having a monodisperse grain size of around 3 nm by an effective ultrasonic liquid phase exfoliation method. Optical studies using UV-Vis, PL, and PLE techniques on the as-prepared TaS 2 QDs exhibited ultraviolet absorption at 283 nm. Furthermore, we found that dimension reduction of TaS 2 has led to a modification of the band gap, namely a transition from indirect to direct band gap, which is explained using first-principle calculations. By using quinine as reference, the fluorescence quantum yield is 45.6%. Therefore, our results suggest TaS 2 QDs have unique and extraordinary optical properties. Moreover, the low-cost, facile method of producing high quality TaS 2 QDs in this work is ideal for mass production to ensure commercial viability of devices based on this material. TaS 2 quantum dots having a monodisperse grain size of around 3 nm have been prepared by an ultrasonic liquid phase exfoliation method, it has been found that the dimension reduction of TaS 2 has led to a transition from indirect to direct band gap that results in the unique and extraordinary optical properties (PL QY: 45.6%).

Low-dimensional semiconductors exhibit remarkable performances in many device applications because of their unique physical, electrical, and optical properties. In this paper, we report a novel and facile method to synthesize In 2 S 3 quantum dots (QDs) at atmospheric pressure and room temperature conditions. This involves the reaction of sodium sulfide with indium chloride and using sodium dodecyl sulfate (SDS) as a surfactant to produce In 2 S 3 QDs with excellent crystal quality. The properties of the as-prepared In 2 S 3 QDs were investigated and photodetectors based on the QDs were also fabricated to study the use of the material in optoelectronic applications. The results show that the detectivity of the device stabilizes at ~ 10 13 Jones at room temperature under 365 nm ultraviolet light irradiation at reverse bias voltage.

Fe-doped ZnO nanoneedles (NDs) were fabricated by an Ar+ ion sputtering technique operated at room temperature. The as-grown samples show both ferromagnetic and lasing properties. The saturated magnetization moment was measured from 0.307 to 0.659 emu cm-3 at the field of 10 kOe with various Fe concentrations. Intense ultraviolet random lasing emission was observed from Zn1 - xFexO NDs at room temperature. The X-ray photoelectron spectroscopy result reveals that the doped Fe atoms occupy the Zn sites and lead to a decrease in oxygen deficiency.