Tunnel junction technology for multijunction solar cell applications

Solar cells are very promising renewable resource. High efficiency of AIIIBV based solar cells are achieved in multijunction constructions. The technology of these devices is very difficult due to the complex electrical and optical interactions between the different semiconductor layers. Usually, the individual subcells are interconnected via Esaki tunnel diodes. This work presents the technology and computer modelling of GaAs based tunnel diodes which will be applied in tandem GaAs/InGaAs solar cells. Designed structures were grown by atmospheric pressure metal organic vapour phase epitaxy. Simulation results as well as dopant profiles and measured DC I-U characteristics of the obtained tunnel diodes are presented and discussed.