Oxygen deficiency and Sn doping of amorphous Ga2O3
Oxygen deficiency and Sn doping of amorphous Ga2O3
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DOI：
10.1063/1.4938473
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发表时间：
2016-01
影响因子：
4
通讯作者：
M. Heinemann;J. Berry;G. Teeter;T. Unold;D. Ginley
中科院分区：
文献类型：
--
作者：
M. Heinemann;J. Berry;G. Teeter;T. Unold;D. Ginley
考虑到其大的带隙，有效的n型掺杂Ga2O3的潜力使其成为集成到晶体管和太阳能电池中的有吸引力的目标。因此，非晶GaOx现在作为太阳能电池中的电子传输层引起了人们的兴趣，尽管关于其光电特性的信息很少。在这里，我们提出的光电性能，包括光学带隙，电子亲和势，和载流子密度，非晶GaOx薄膜沉积的脉冲激光沉积。这些性质强烈依赖于沉积过程中的沉积温度。沉积温度对薄膜的一般结构性质没有显著影响，但会使薄膜的氧化学计量发生显著变化。发现氧空位的密度与GaOx层的光学带隙有关。据认为，氧的缺乏导致缺陷带低于导带最低值，增加了电子亲和势。这些性质有利于使用非晶GaOx作为Cu（In，Ga）Se2和Cu2O太阳能电池中的电子传输层。此外，它示出，在低沉积温度下，与Sn的非本征掺杂是有效的，在低Sn浓度。
The potential of effectively n-type doping Ga2O3 considering its large band gap has made it an attractive target for integration into transistors and solar cells. As a result amorphous GaOx is now attracting interest as an electron transport layer in solar cells despite little information on its opto-electrical properties. Here we present the opto-electronic properties, including optical band gap,electron affinity, and charge carrier density, for amorphous GaOx thin films deposited by pulsed laser deposition. These properties are strongly dependent on the deposition temperature during the deposition process. The deposition temperature has no significant influence on the general structural properties but produces significant changes in the oxygen stoichiometry of the films. The density of the oxygen vacancies is found to be related to the optical band gap of the GaOx layer. It is proposed that the oxygen deficiency leads to defect band below the conduction band minimum that increases the electron affinity. These properties facilitate the use of amorphous GaOx as an electron transport layer in Cu(In,Ga)Se2 and in Cu2O solar cells. Further it is shown that at low deposition temperatures, extrinsic doping with Sn is effective at low Sn concentrations.