Effect of controlled dopant distribution in thin silicon solar cell

Dopant incorporation leading to drift field in a thin silicon solar cell may be controlled and compensated suitably to produce positive or negative drift field. A positive drift field at the base increases short-circuit current density simultaneously decreasing open-circuit voltage, resulting in some net benefit in efficiency for unpassivated front and back surface. In case of well-passivated front and back, however, positive drift field may result in a marginal drop in efficiency. If the dopant incorporation is compensated to produce a small negative drift field, open-circuit voltage increases to such an extent that the overall effect is an increase in efficiency for moderately passivated front and back. Moderate passivation and small negative field seems to produce the best results. The effect may yield 10% gain in overall efficiency for thin cells. Methods of incorporating small negative drift field in LPE grown thin silicon cells are also suggested.