Fabrication and characterisation of 662-mV open-circuit voltage high-efficiency inversion-layer silicon solar cells

High-efficiency inversion-layer silicon solar cells are described where the contact to the inversion layer is made via a diffused p-n junction. Silicon nitride (SiN) films are deposited at 250°C or 375°C onto the front surface, resulting in strongly differing surface passivation and inversion-layer properties. A record-high open-circuit voltage for inversion-layer solar cells of 662 mV on 0.5 Ωcm float-zone p-silicon is obtained for the 375°C SiN films. The performance properties of these 16% efficient inversion-layer solar cells are analyzed by means of 2D numerical modeling. An analytical model is developed for the perimeter recombination current via the inversion-layer emitter. Good agreement between measured and simulated dark and 1-sun current-voltage curves is obtained, allowing for the determination of the dominant power and recombination losses in the experimental solar cells