The range of high-efficiency silicon solar cells fabricated at Fraunhofer ISE

An overview of the high-efficiency solar cell developments with crystalline silicon at Fraunhofer ISE (Germany) is given. Seven types of solar cells are discussed: (1) LBSF cells (local back surface field); (2) RP-PERL cells (random pyramids, passivated emitter rear locally-diffused); (3) RP-PERC (random pyramids, passivated emitter and rear cell); (4) MESC (mesh-structured emitter cell): (5) cells with interdigitated contacts; (6) high-efficiency thin film solar cells based on SOI (silicon on insulator); and (7) mini modules integrated on one 4" SOI-wafer. All these cells show very good efficiencies close to or well above 20%, respectively. The goal of all activities is to develop technologies for efficiencies as high as possible but at the same time as simple as possible. Many of the developments are performed in close cooperation with German PV companies and/or with European research teams in the framework of projects of the European Commission.