Laser Grooved Buried Contact Solar Cells for Concentration Factors up to 100x

The laser grooved buried contact (LGBG) crystalline silicon solar cell is an attractive technology for the production of low-cost concentrator cells. Due to the high-conductivity buried front contact, the metallization pattern may be readily adapted to handle the larger current densities produced at higher concentrations whilst minimizing shading. In the 1990´s an efficiency of 18% at 30X concentration without prismatic covers was demonstrated in the EUCLIDES concentrator system. A matrix of cell process conditions has been investigated in order to optimize the emitter and front contact design of the LGBC cell for concentration factors of 50-100X. Efficiencies over 18% at 50X concentration have been measured on 2.56 cm² cells. Factors limiting the efficiency are discussed and processing improvements are suggested