Many-body effects-driven intermediate band states in intercalated 2D Cu_xGeSe/SnS heterostructure

Through advanced ab initio many-body computations and materials modeling, we design a new generation of quantum photovoltaic materials through intercalation of zerovalent copper atoms into atomically thin GeSe/SnS heterostructure. The designed material exhibits quasi-localized intermediate band states which are governed by many-body interactions. Our calculations highlight a notable improvement in the optical spectra, specifically in the crucial 400 to 600 nm wavelength range spanning near-infrared to visible solar wavelengths. Moreover, a prototype thin-film solar cell with this material as its active layer achieves an external quantum efficiency (EQE) of up to 190%.