“类金字塔”状ZnO改善硅异质结电池近红外波段外量子效率

Improvement of External Quantum Efficiency for Silicon Heterojunction Cell in the Near-infrared Band Improved by "Pyramid" Morphology ZnO

因晶体硅是间接带隙半导体材料,其较低的吸收系数限制了对近红外波段入射光的吸收。为此,引入金属有机化学气相沉积(MOCVD)技术制备的Zn O薄膜,并通过改变掺杂流量和沉积时间调节Zn O∶B(BZO)薄膜的光学和电学性能。将BZO薄膜用于硅异质结(SHJ)太阳电池的背反射电极,相比于传统结构,电池的反射率和外部量子效率在近红外波段得到显著改善。为进一步解释外量子效率增加的原因,在四甲基氢氧化铵(TMAH)湿法制绒的硅衬底上沉积BZO薄膜,得到了新型微纳米嵌套结构,并对其光吸收进行了测试分析。

Crystalline silicon has a lower absorption coefficient, which is ascribed to the indirect bandgap of materials, thus limits the absorption of incident light of near-infrared band. Therefore, the ZnO thin film deposited by metal organic chemical vapor deposition （MOCVD） was introduced and optical properties of ZnO： B（BZO） films were adjusted by changing doping flow and deposition time. A and electrical ppling this film to heterojunction（SHJ） solar cell resulted in significant improvement of the external quantum efficiency and reflectance. In order to further explain the reason of improvement, BZO thin film was deposited on the texturing silicon substrates obtained by tetramethylammonium hydroxide （TMAH） solution, a new nanometer- and micrometer-scale structure was obtained, and its light absorption was measured and analyzed.