Arrayed CdTeMicrodots and Their Enhanced Photodetectivity via Piezo-Phototronic Effect

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Photodetectors are crucial optoelectronic devices.
• Piezo-phototronic effect offers novel device functionalities.
• Cadmium telluride (CdTe) is a promising semiconductor material.

Purpose of the Study:

• To fabricate and characterize a photodetector based on arrayed CdTe microdots.
• To investigate the effect of mechanical stress on photodetector performance.
• To explore the application of the piezo-phototronic effect in CdTe microdot photodetectors.

Main Methods:

• Fabrication of CdTe microdots on bismuth (Bi)-coated indium tin oxide (ITO)/glass substrates.
• Measurement of current-voltage characteristics under normal and stressed conditions.
• Analysis of photoinduced current and photoresponsivity changes.

Main Results:

• The photodetector exhibited ultrahigh sensitivity under mechanical stress.
• Photoinduced current increased from 20 to 76 μA cm⁻² under stress.
• Photoresponsivity enhanced from 3.2 × 10⁻⁴ A/W to 5.5 × 10⁻³ A/W at 5 V bias.
• Observed changes attributed to piezopotential-induced Schottky barrier height modulation via the piezo-phototronic effect.

Conclusions:

• CdTe microdot photodetectors show significantly enhanced performance under stress.
• The piezo-phototronic effect is a viable mechanism for improving photodetector sensitivity.
• This work demonstrates a facile and promising approach for developing advanced photodetectors.