Silicon nitride for the improvement of silicon inversion layer solar cells

It is demonstrated that CVD Si-nitride films as transparent dielectric satisfy all requirements for achieving MIS/IL solar cells with high efficiency and long term stability. Deposited on silicon by the SiH₄/NH₃ reaction at temperatures lower than usual (between 600° and 650°C) fixed positive interface charge densities Q_N/q up to 7 × 10¹² cm^?2 with excellent stability have been obtained. Utilizing the Si-nitride charge storage effect, the highest known Q_N/q values (> 10¹³cm^?2) combined with low values of N_it have been achieved. The charge distribution is discussed and an energy band diagram modified according to new analytical results is presented. MIS/IL solar cells with AM1 efficiencies of 15% (active area) and high UV sensitivity have been obtained.