High-efficiency piezo-phototronic solar cells by strain-induced polarization

Toward high power-conversion efficiency (PCE) of a two-dimensional (2D) material solar cell requires carrier and light-management technologies. By strain-induced polarization of piezotronic and piezo- phototronic effect, under the standard AM1.5G solar spectrum, the maximum theoretical PCE is 54.4% of SnS among the 2D piezoelectric semiconductors, such as SnS, MoS2, GeS, WS2, WSe2, and MoSe2. PCEs of solar cells with 2D WS2 and MoS2 are boosted to 48.1% and 42.8%, respectively. Strain-induced polarization will not only increase the built-in field, but also simplify bandgap gradients by inexpensive strain regulation. In this article, we propose the tandem and parallel piezo-phototronic solar cell (PSC) with single-type 2D piezoelectric semiconductor materials. This work provides a novel way to develop an ultrahigh efficiency 2D material solar cell. Impact statement High-performance piezotronic and piezo-phototronic solar cells have been developed by strain-induced polarization. Nonuniform strain can effectively enhance piezoelectric polarization to improve power-conversion efficiency (PCE) of piezotronic solar cells. Toward high PCE of a two-dimensional (2D) material solar cell requires carrier and light-management technologies. By the strain-induced polarization of piezotronic and piezo-phototronic effect, cell PCEs based on 2D WS2 and MoS2 are boosted to 48.1% and 42.8%, respectively. Strain-induced polarization will not only increase the built-in field, but also simplify bandgap gradients by inexpensive strain regulation. In this article, we propose the tandem and parallel piezo-phototronic solar cell with single-type 2D piezoelectric semiconductor materials. This work not only provides a novel way to develop an ultrahigh efficiency 2D material solar cell, but also overcome the limitation of Shockley-Queisser for single material solar cells.