Analysis and optimisation of the glass/TCO/MZO stack for thin film CdTe solar cells
Analysis and optimisation of the glass/TCO/MZO stack for thin film CdTe solar cells
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DOI：
10.1016/j.solmat.2018.07.019
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发表时间：
2018-12-01
影响因子：
6.9
通讯作者：
Walls, John M.
中科院分区：
文献类型：
--
作者：
Bittau, Francesco;Potamialis, Christos;Walls, John M.
镁掺杂的氧化锌（MZO）薄膜最近被提出作为用于薄膜CdTe太阳能电池的透明缓冲层。在这项研究中，MZO缓冲层的带隙调谐的碲化镉太阳能电池，通过增加沉积过程中的衬底温度。薄膜采用射频磁控溅射法制备。包含在300摄氏度下沉积的具有3.70 eV带隙的优化MZO缓冲层的器件产生12.5%的平均效率和13.3%的最高效率。透射电子显微镜显示MZO薄膜均匀沉积在透明导电氧化物（TCO）层表面。有利的能带排列似乎积极地抵消了MZO层的低掺杂水平及其与CdTe的高晶格失配。钛掺杂的氧化铟、锡掺杂的氧化铟和铝掺杂的氧化锌TCO也被用作与MZO膜组合的氟掺杂的氧化锡（FTO）的替代物。与FTO相比，使用钛掺杂的氧化铟和锡掺杂的氧化铟TCO没有提高所实现的器件效率，然而，使用铝掺杂的氧化锌与硼铝硅酸盐玻璃基板结合，平均和最高效率分别进一步提高到12.6%和13.4%。
Magnesium-doped Zinc Oxide (MZO) films have recently been proposed as a transparent buffer layer for thin film CdTe solar cells. In this study, the band gap of MZO buffer layers was tuned for CdTe solar cells by increasing the substrate temperature during deposition. Films were deposited by radio-frequency magnetron sputtering. Devices incorporating an optimised MZO buffer layer deposited at 300 degrees C with a band gap of 3.70 eV yielded a mean efficiency of 12.5% and a highest efficiency of 13.3%. Transmission electron microscopy showed that MZO films are uniformly deposited on the transparent conductive oxide (TCO) layer surface. The favourable band alignment seems to positively counterbalance the low doping level of the MZO layer and its high lattice mismatch with CdTe. Titanium-doped indium oxide, tin-doped indium oxide and aluminium-doped zinc oxide TCOs were also used as alternatives to fluorine-doped tin oxide (FTO), in combination with MZO films. The use of titanium-doped indium oxide and tin-doped indium oxide TCOs did not improve the device efficiency achieved compared with FTO, however using aluminium-doped zinc oxide coupled with a boro-aluminosilicate glass substrate the mean and highest efficiencies were further improved to 12.6% and 13.4% respectively.