Visible to Short-Wave Infrared Photodetectors Based on ZrGeTe4 van der Waals Materials

The self-terminated, layered structure of van der Waals materials introduces fundamental advantages for infrared (IR) optoelectronic devices. These are mainly associated with the potential for low noise while maintaining high internal quantum efficiency when reducing IR absorber thicknesses. In this study, we introduce a new van der Waals material candidate, zirconium germanium telluride (ZrGeTe4), to a growing family of promising IR van der Waals materials. We find the bulk form ZrGeTe4 has an indirect band edge around similar to 0.5 eV, in close agreement with previous theoretical predictions. This material is found to be stable up to 140 degrees C and shows minimal compositional variation even after >30 days storage in humid air. We demonstrate simple proof-of-concept broad spectrum photodetectors with responsivities above 0.1 AW(-1) across both the visible and short-wave infrared wavelengths. This corresponds to a specific detectivity of similar to 10(9) cm Hz(1/2) W-1 at lambda = 1.4 mu m at room temperature. These devices show a linear photoresponse vs illumination intensity relationship over similar to 4 orders of magnitude, and fast rise/fall times of similar to 50 ns, also verified by a 3 dB roll-off frequency of 5.9 MHz. As the first demonstration of photodetection using ZrGeTe4, these characteristics measured on a simple proof-of-concept device show the exciting potential of the ZrGeTe4 for room temperature IR optoelectronic applications.

Automated summary

The study introduces a new candidate van der Waals material, zirconium germanium telluride (ZrGeTe4), with stable structure and high detectivity for infrared optoelectronic devices. Devices exhibit linear photoresponse, fast response times, and high efficiency.