Strain‐Enhanced Photovoltaic Effect in MoTe 2

Abstract The recent development of two‐dimensional (2D) materials has demonstrated that by using the bulk photovoltaic effect (BPVE) for crystals lacking inversion symmetry, it is possible to overcome the Shockley–Queisser limit. So far, the exploration of 2D p–n junction designs have recently been extensively investigated. However, the mechanism of BPVE differs from traditional p–n junction‐based photovoltaics in 2D materials. This paper presents the first experimental demonstration of the bulk photovoltaic effect in 1T′‐MoTe 2 . The measured intensity dependence V oc and I sc display a direct relationship to the incident light (power: 20 to 120 W cm −2 ; wavelengths: 400, 450, 500 nm). In 1T′‐MoTe 2 nanoflakes on flexible polyimide, astrain‐enhanced BPVE is seen, producing a BPVE response of 3.60 mV. In addition, the BPVE tensor value increased from 259 to 527 A W −1 for unstrained 1T′‐MoTe 2 while it increased from 467 to 882 A W −1 for strained 1T′‐MoTe 2 as the wavelength decreased from 500 to 400 nm. The results show a new way to improve the efficiency of turning energy into electricity in new optoelectronic materials.