LIMITS FOR THE MAXIMUM EFFICIENCY OF SILI CON SOLAR-CELLS - EFFECTS DUE TO AUGER GENERATION AND TO DEEP LEVELS

We discuss how the maximum efficiency for silicon solar cells will be changed by the impurity photovoltaic (IPV) and the Auger generation ef fects, phenomena that have been observed experimentally lately. Our re sults indicate that the IPV effect causes a reduction of the upper eff iciency limit, confirming the suggestion made in the past for avoiding this mechanism to improve the efficiency, while the Auger generation (of electron-hole pairs by hot carriers) causes only a small beneficia l improvement for such limit. In order to do the above calculations we have developed a new version of the detailed balance theory which is simple and more in accordance with a modern notation in the solar cell s field. This theory can be used to determine how the maximum efficien cy may be improved for cells based on other semiconductors when the ab ove effects are taken into account.