Local electrical characterization of cadmium telluride solar cells using low-energy electron beam
Local electrical characterization of cadmium telluride solar cells using low-energy electron beam
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DOI：
10.1016/j.solmat.2013.07.024
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发表时间：
2013-10
影响因子：
6.9
通讯作者：
H. Yoon;Paul M. Haney;D. Ruzmetov;Hua Xu;Marina S. Leite;B. Hamadani;A. Alec Talin;N. Zhitenev
中科院分区：
文献类型：
--
作者：
H. Yoon;Paul M. Haney;D. Ruzmetov;Hua Xu;Marina S. Leite;B. Hamadani;A. Alec Talin;N. Zhitenev
我们用电子束感应电流(EBIC)测量图案化接触的方法研究了碲化镉太阳电池的局部电子性质。在器件的顶表面和整个横截面上，EBIC测量的空间分辨率都高达≈20 nm，显示出p结附近显著程度的电不均匀，以及晶界(GB)附近增强的载流子收集。低能EBIC的模拟结果表明，1 GB附近的能带弯曲是向下的，对于最有效的集电GBs，其量级至少为0.2 eV。此外，我们展示了一种新的方法来研究局部开路电压，方法是通过点电子束注入在电触点上施加外部偏置。纳米接触的长度在单个或几个颗粒的长度尺度上，用高度局域的光生载流子限制了电流路径。
We investigate local electronic properties of cadmium telluride solar cells using electron beam induced current (EBIC) measurements with patterned contacts. EBIC measurements are performed with a spatial resolution as high as ≈20 nm both on the top surface and throughout the cross-section of the device, revealing a remarkable degree of electrical inhomogeneity near thep–njunction and enhanced carrier collection in the vicinity of grain boundaries (GB). Simulation results of low energy EBIC suggest that the band bending near a GB is downward, with a magnitude of at least 0.2 eV for the most effective current-collecting GBs. Furthermore, we demonstrate a new approach to investigate local open-circuit voltage by applying an external bias across electrical contact with a point electron-beam injection. The length scale of the nanocontacts is on the length scale of a single or a few grains, confining current path with highly localized photo-generated carriers.