摘要 |
A photovoltaic device comprises an interface (8) between a layer of Group lll-V material (3) and a layer of Group IV material (1) with a thin silicon diffusion barrier (6) provided at or near the interface. The silicon barrier controls the diffusion of Group V atoms into the Group IV material, which is doped n-type thereby. The n-type doped region can provide the p-n junction of a solar cell in the Group IV material with superior solar cell properties. It can also provide a tunnel diode in contact with a p-type region of the lll-V material, which tunnel diode is also useful in solar cells. In another aspect, a multijunction photovoltaic device is provided in which there are at least a first light-absorbing layer (111) of SiGe or SiGeSn and a second light-absorbing layer (112) of SiGeSn, both layers being lattice-matched to GaAs. |