Laminated grid solar cells (LGCells) on multicrystalline silicon. Application of atomic hydrogen treatment

Abstract

For the first time, solar cells of laminated grid cell (LGCell) design are fabricated on multicrystalline nontextured silicon (mc-Si). An efficiency of 15.9% is achieved. The effect of (n + pp +)-mc-Si structure treatment by atomic hydrogen generated by a hot filament and microwave plasma is studied. Hydrogenation improves the parameters describing the dependence of the open-circuit voltage on the radiation intensity and the long-wavelength (λ = 1000 nm) sensitivity of the solar cell by 10–20%, which indicates that defects in mc-Si are passivated. Hydrogenation of the emitter side results in an increase in the series resistance of the solar cell, a decrease in the short-wavelength (λ = 400 nm) sensitivity by 30–35%, and the appearance of an oxygen peak in the energy-dispersive spectra (EDS). These effects are eliminated by fine etching of the emitter.