The influence of plasma and surface inhomogeneities on batch-deposited ultrathin amorphous silicon solar cells

The deposition of ultrathin amorphous silicon ( a- Si:H) solar cells on textured substrates introduces challenges in maintaining optimal device performance due to defect-prone interfaces. This work aims at identifying and addressing the issues associated with the fabrication of ultrathin a- Si:H (absorber layer of 100 nm) solar cells on quasiperiodic textured surfaces. Batches of solar-cell devices were fabricated on four distinct designs of quasiperiodic nanowrinkle textures, and their optical and electrical responses were obtained experimentally. The best device reported ∼8 % efficiency with nearly 15 mA cm −2 short-circuit current density. Using the measured characteristics of their surface morphologies as a guide, mathematical models of the growth profile of device layers on the four nanowrinkle designs were formulated, which were integrated into the optical and electrical modeling of the batches of ultrathin devices. By examining the relation between the layer characteristics and the device performance of ultrathin solar-cell devices with two window-layer types, the study offers critical insights into the selection of optimal textures and strategies for device design. A device architecture with a nanocrystalline p -layer overlaying a thin protective amorphous p -layer offers minimal electrical losses and enhances power conversion efficiencies when deposited on the nanowrinkle textures. • High efficiency ultrathin a-Si:H solar cell on low-cost, scalable nanowrinkles. • Numerical models of layer growth, optical and device performance carried out. • A thin protective a-Si:C:H/nc-Si:H p-layer improves FF of highly textured devices. • Decoupling of effect of surface and plasma inhomogeneities on textured devices. • A framework for selecting growth conditions to reduce performance-limiting factors.