High open-circuit voltage in transition metal dichalcogenide solar cells

The conversion efficiency of ultra-thin solar cells based on layered materials has been limited by their open-circuit voltage, which is typically pinned to a value under 0.6 V. Here we report an voltage 1.02 V in 120 nm-thick vertically stacked homojunction fabricated with substitutionally doped MoS2. This high consistent the band alignment MoS2 homojunction, more favourable than widely-used TMDC heterostructures. It also attributed performance MoS2, particular p-type material Nb, demonstrated observation electroluminescence from tunnelling graphene/BN/MoS2 structures spite indirect nature bulk We find that illuminating TMDC/metal contacts decreases measured van der Waals homojunctions because they are photoactive, points need developing low-resistance, ohmic order achieve practical devices. here confirms potential transition-metal dichalcogenides for development highly efficient, cells.