High-performance stretchable photodetectors based on epitaxial CdTe ultrathin films

Abstract

Due to its striking optical, electrical and mechanical properties, cadmium telluride (CdTe) has received tremendous interest in developing next-generation optoelectronic devices. However, stretchable photodetectors (PDs) based on high-quality CdTe films are still challenging. Herein, single-crystalline (111)-oriented CdTe ultrathin films are grown epitaxially onto the surface of NaCl by using a sputtering method. Through designing the exfoliation and transfer procedure of the centimeter level film from the NaCl crystal onto the PDMS template, stretchable CdTe PDs are fabricated successfully. The PDs have a broadband photoresponse in the wavelength range of 404–808 nm, especially displaying a high photoresponsivity of 127.2 mA W⁻¹, a high photodetectivity of 9.1 × 10¹⁰ Jones under 650 nm-laser irradiation and fast response rates. Significantly, the CdTe PDs exhibit excellent mechanical durability over 200 stretching cycles and high environmental stability. This work provides novel strategies to develop high-performance wearable CdTe optoelectronic devices.