Comparison of anti-reflective properties of single layer anatase and rutile TiO_2 on GaAs based solar cells
Comparison of anti-reflective properties of single layer anatase and rutile TiO_2 on GaAs based solar cells
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单层锐钛矿型和金红石型TiO_2在GaAs基太阳能电池上减反射性能的比较
DOI：
10.1557/adv.2016.116
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发表时间：
2016
期刊：
影响因子：
0.8
通讯作者：
M. O. Manasreh
中科院分区：
文献类型：
--
作者：
R. Vasan;Y. F. Makableh;M. O. Manasreh
本文研究了低温生长的锐钛矿型和金红石型二氧化钛薄膜作为GaAs太阳电池的单层镀膜。薄膜是通过旋涂一层TiO_2溶胶-凝胶，然后在150 °C下退火得到的。溶胶-凝胶是由异丙醇钛在酸或碱存在下水解而成。通过控制生长过程中溶胶-凝胶的pH值，可以得到纯的金红石相和金红石相。当pH值为3.0左右时，得到的是金红石型TiO_2，而pH值为9.0时，得到的是纯金红石型TiO_2。通过测量拉曼散射光谱对两种不同相的TiO_2进行了表征。用椭圆偏振光谱仪测量了GaAs薄膜的光学常数、厚度和反射率。将溶胶-凝胶旋涂在基于GaAs的太阳能电池上，并在150 °C下退火以形成抗反射层。对薄膜制备前后电池的性能进行了评价。金红石型TiO_2增透膜的性能优于金红石型增透膜，最大功率转换效率提高了50%。在金红石相和金红石相薄膜中，量子效率分别提高了58%和25%。使用这些薄膜的太阳能电池的性能增强可以归因于与太阳能电池表面上的单层涂层相关联的光的相消干涉。
Anatase and rutile titanium dioxide thin films grown by a low temperature process are investigated for their use as a single layer antireflection coating for GaAs solar cells. The thin films are obtained by spin coating a layer from the TiO_2 sol-gel and subsequently annealing at 150 °C. The sol-gel is synthesized by the hydrolysis of titanium isopropoxide in the presence of an acid or a base. By controlling the pH of the sol-gel during growth, pure anatase and rutile phases are obtained. A pH of around 3.0 yields anatase phase while a pH of 9.0 yields pure rutile phase TiO_2. The two different phases of TiO_2 are characterized by measuring the Raman scattering spectra. The optical constants, thickness and reflectance of the thin films on GaAs are obtained using a spectroscopic ellipsometer. The sol-gel is spin coated on GaAs based solar cells and annealed at 150 °C to form the anti-reflective layer. The performance of the solar cells is evaluated before and after coating with the TiO_2 films. The anatase TiO_2 anti-reflective films performed better than the rutile with a maximum power conversion efficiency enhancement of 50%. Quantum efficiency enhancement of 58% and 25% are obtained with anatase and rutile phase films respectively. The performance enhancement of the solar cells using these thin films can be attributed to the destructive interference of light associated with a single layer coating on the solar cell surface.