Self-Catalyzed CdTe Wires

An In-Depth Analysis of CdTe Thin-Film Deposition on Ultra-thin Glass Substrates via Close-Spaced Sublimation (CSS)

This study evaluated the impact of the deposition pressure on the formation of cadmium telluride (CdTe) thin films on ultra-thin (100 µm) Schott glass substrate at high temperature (T > 450 °C) by Close-Spaced Sublimation (CSS) technique. CdTe thin films were grown under the pressure range of 1 Torr to 200 Torr to explore the impact of deposition pressure on CdTe thin-film properties. The microstructural, compositional and optoelectrical characteristics were examined. X-ray Diffraction (XRD) analysis revealed the cubic phase crystallite CdTe films with (111) preferential orientation. Scanning Electron Microscopy (SEM) demonstrated that the CdTe morphology and grain size could be regulated via the deposition pressure, whereby maximum grain growth was detected at low pressure (1–5 Torr). The thickness of CdTe films was reduced from 6 µm to 1.5 µm with the rise in deposition pressure. Moreover, the optical direct energy gap was derived in the range of 1.65–1.69 eV for the pressure value of 200 Torr to 1 Torr. Carrier density and resistivity were found to be in the order of 1013 cm−3 and 104 Ω cm, respectively. The experimental results suggest that the pressure range of 1–5 Torr may be ideal for CSS-grown CdTe films on flexible ultra-thin glass (UTG) substrates.

Arrayed CdTeMicrodots and Their Enhanced Photodetectivity via Piezo-Phototronic Effect

In this paper, a photodetector based on arrayed CdTe microdots was fabricated on Bi coated transparent conducting indium tin oxide (ITO)/glass substrates. Current-voltage characteristics of these photodetectors revealed an ultrahigh sensitivity under stress (in the form of force through press) while compared to normal condition. The devices exhibited excellent photosensing properties with photoinduced current increasing from 20 to 76 μA cm-2 under stress. Furthermore, the photoresponsivity of the devices also increased under stress from 3.2 × 10-4 A/W to 5.5 × 10-3 A/W at a bias of 5 V. The observed characteristics are attributed to the piezopotential induced change in Schottky barrier height, which actually results from the piezo-phototronic effect. The obtained results also demonstrate the feasibility in realization of a facile and promising CdTe microdots-based photodetector via piezo-phototronic effect.