1eV吸收带边GaInAs/GaNAs超晶格太阳能电池的阱层设计

Well layer design for 1eV absorption band edge of GaInAs/GaNAs super-lattice solar cell

使用In,N分离的GaInAs/GaNAs超晶格作为有源区是实现高质量1eV带隙GaInNAs基太阳能电池的重要方案之一.为在实验上生长出高质量相应吸收带边的超晶格结构,本文采用计算超晶格电子态常用的Kronig-Penney模型比较了不同阱层材料选择下,吸收带边为1 eV的GaInAs/GaNAs超晶格相关参数的对应关系以及超晶格应变状态.结果表明:GaNAs与GaInAs作为超晶格阱层材料在实现1 eV的吸收带边时具有不同的考虑和要求;在固定1 eV的吸收带边时,GaNAs材料作为阱层可获得较好的超晶格应变补偿,将有利于生长高质量且充分吸收的太阳能电池有源区.

The GalnAs/GaNAs super-lattice with a feature of space separation of In and N constituents as an active region, is one of the most important ways to achieve 1 eV GalnNAs-based solar cells. To experimentally realize the high-quality super-lattice structure with the required band-gap, Kronig-Penney model is used to obtain the barrier thickness dependence on the well thickness and its composition. Meanwhile, the strain state of GalnAs/GaNAs SLs with various well choices is also discussed. Results show that when both the GaNAs and GalnAs act as the well layers the super-lattice can achieve 1 eV band-gap, and when the GaNo.04Aso.96 is considered to act as the well layer, the entire GalnAs/GaNAs SLs have smaller strain accumulations as compared with the case of Gao.7Ino.aAs as the well layer in the super-lattice structure.