Low-temperature preparation of flexible a-Si:H solar cells with hydrogenated nanocrystalline silicon p layer

► Flexible a-Si:H thin film solar cells were prepared on PEN substrates using p-nc-Si:H thin film as the window layers. ► p-nc-Si:H thin films (∼60 nm) were deposited at 150 °C using TMB as a dopant gas. ► The RMS roughness of silicon thin film increased when the crystalline fraction decreased. ► For the a-Si:H solar cells on PEN substrate, the best initial efficiency of 6.3% was achieved.