Design and fabrication process flow for high-efficiency and flexible InGaN solar cells

We present the design of high-efficiency and flexible InGaN solar cells based on nano-pyramid absorbers, which allows for high indium incorporation and reduced polarization effects while maintaining high crystalline quality. The process uses nanoscale selective area growth and van der Waals epitaxy on two-dimensional (2D) hexagonal boron nitride on sapphire substrates. The 2D layer enables mechanical release of solar cells via self-lift-off and its transfer to a flexible substrate. Through coupled optical and electrical simulations, we compare different designs of the p- and n-regions and propose two device architectures that combine mechanical flexibility and high power conversion efficiency (up to 16.4%). This approach can provide a solution for the fabrication of high-efficiency, low-cost and flexible InGaN-based solar cells.