多接合型化合物半導体太陽電池の現状と将来展望

摘要

III-V compound multi-junction solar cells have great potential of power generation for space and terrestrial applications, since they have high conversion efficiencies over 30%, which is the maximum conversion efficiency obtained by a single junction solar cell. So far, 36.9% conversion efficiency under the one sun, and 43.5 % under 400 concentrated light have been achieved by the three junction tandem solar cells. In order to realize the next generation multi-junction solar cells with super high efficiencies over 45%, we are studying the lattice match four junction solar cells using new materials such as InGaAsN and the lattice mismatched three junction solar cells. This paper reviews the recent technologies and materials for multi-junction solar cells with super high efficiencies.%単接合太陽電池の限界を超える高い変換効率を実現できる多接合型太陽電池は，宇宙用での用途に加えて，集光システムとの組み合わせにより地上での発電用として精力的に開発が進められている。今後，さらに低コストで高効率な多接合太陽電池やそれを用いた集光発電システムを実現するには，材料，半導体，機械，熱，光学など多くの分野の協力が必要不可欠である。