Improving the characteristics of intermediate-band solar cell devices using a vertically aligned InAs/GaAsSb quantum dot structure
Improving the characteristics of intermediate-band solar cell devices using a vertically aligned InAs/GaAsSb quantum dot structure
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DOI：
10.1016/j.solmat.2012.06.023
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发表时间：
2012-10-01
影响因子：
6.9
通讯作者：
Chyi, Jen-Inn
中科院分区：
文献类型：
--
作者：
Liu, Wei-Sheng;Wu, Hong-Ming;Chyi, Jen-Inn
本研究论证了通过在InAs量子点上覆盖GaAsSb层来改善垂直排列量子点(QD)结构的光学性质和量子点中间带太阳电池(QD-IBSC)性能的可行性。实验结果表明，在连续垂直排列点层生长的演化过程中，应变修正显著改善了网点尺寸的均匀性。与参考电池相比，具有InAs/GaAsSb柱状点结构的太阳电池器件的短路电流密度(J(Sc))提高了8.8%。这种点结构还通过吸收较低能量的光子将量子效率提高了高达1200纳米。InAs/GaAsSb QD-IBSC还改善了开路电压(V-oc)，表明失配缺陷密度和复合电流密度降低。研究结果证实了柱状InAs/GaAsSb量子点结构能够提高器件的性能。(C)2012爱思唯尔B.V.保留所有权利。
This study demonstrates the feasibility of improving the optical properties of a vertically aligned quantum dot (QD) structure and the performance of a quantum dot intermediate band solar cell (QD-IBSC) by capping a GaAsSb layer on the InAs QDs. Experimental results indicate that dot-size uniformity is significantly improved due to the strain modification in the evolution of the successive vertically aligned dot layer growth. A solar cell device with an InAs/GaAsSb columnar dot structure increases the short-circuit current density (J(sc)) by 8.8%, compared to a GaAs reference cell. This dot structure also increases quantum efficiency by up to 1200 nm through the absorption of lower-energy photons. The InAs/GaAsSb QD-IBSC also improves the open-circuit voltage (V-oc), indicating a reduction in misfit defect density and recombination current density. The results of this study confirm the ability of a columnar InAs/GaAsSb QD structure to enhance the device performance. (c) 2012 Elsevier B.V. All rights reserved.