Relationship between the electrical properties of the n-oxide and p-Cu2O layers and the photovoltaic properties of Cu2O-based heterojunction solar cells
Relationship between the electrical properties of the n-oxide and p-Cu2O layers and the photovoltaic properties of Cu2O-based heterojunction solar cells
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DOI：
10.1016/j.solmat.2015.11.033
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发表时间：
2016-04
影响因子：
6.9
通讯作者：
T. Minami;T. Miyata;Y. Nishi
中科院分区：
文献类型：
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作者：
T. Minami;T. Miyata;Y. Nishi
我们研究了Al掺杂ZnO（AZO）/n-氧化物/p-Cu 2 O异质结太阳能电池的电学性质（n-氧化物半导体层和p-Cu 2 O片）与可获得的光伏性质之间的关系，所述Al掺杂ZnO（AZO）/n-氧化物/p-Cu 2 O异质结太阳能电池使用p型非掺杂Cu 2 O或Na掺杂Cu 2 O（Cu 2 O：Na）片（通过热氧化Cu片制备）作为活性层以及基板来制造。采用脉冲激光沉积（PLD）方法，在不同的O2或O3气氛压力下，制备了不同电子浓度（N）的p-Cu 2 O（非掺杂）片和n-ZnO薄膜的异质结太阳能电池。当N从1017增加到约3× 1019 cm −3时，所得的光伏性能表现出增加的趋势;当N增加到约8× 1019 cm −3时，其值保持在这些最大水平，然后随着N的进一步增加而降低。当anNon为1020 cm −3量级时，光伏特性的降低归因于n-ZnO和p-Cu 2 O层之间界面处导带不连续性的增加。此外，我们还发现Cu_2O：Na片中的空穴浓度（P）（即，通过改变退火温度和退火时间，可以将不同Na化合物退火后的Cu 2 O片的厚度控制在1014 ~ 1019 cm-3范围内。作为另一个例子，在通过PLD在p-Cu 2 O：Na片上沉积n-（Ga0.975Al0.025）2 O3薄膜而制造的异质结太阳能电池中，当P增加到约1× 1016 cm-3时，所获得的光伏特性保持恒定，然后当P进一步增加时，它们显著降低。使用aP高于约1.4× 1016 cm-3的Cu 2 O：Na片制造的异质结太阳能电池中所获得的光伏特性的降低主要归因于耗尽层宽度和扩散长度两者的减小。
We investigated the relationship between the electrical properties (of the n-oxide semiconductor layer and the p-Cu2O sheet) and the obtainable photovoltaic properties of Al-doped ZnO (AZO)/n-oxide/p-Cu2O heterojunction solar cells that were fabricated using either p-type non-doped Cu2O or Na-doped Cu2O (Cu2O:Na) sheets (prepared by thermally oxidizing a Cu sheet) functioning as the active layer as well as the substrate. We fabricated some heterojunction solar cells using p-Cu2O (non-doped) sheets and n-ZnO thin films with various electron concentrations (N) in the range of 1017―1020cm−3; non-doped and Al- or Cu-doped ZnO thin films were deposited under various O2or O3gas atmosphere pressures using a pulsed laser deposition (PLD) method. The obtained photovoltaic properties exhibited a tendency to increase asNwas increased from 1017to about 3×1019cm−3; the values remained at these maximum levels asNwas increased to about 8×1019cm−3, and then they decreased asNwas increased further. With anNon the order of 1020cm−3, the reduction of photovoltaic properties was attributed to an increase in the discontinuity of the conduction band at the interface between the n-ZnO and p-Cu2O layers. In addition, we found that the hole concentration (P) in Cu2O:Na sheets (i.e., Cu2O sheets postannealed with various Na compounds) could be controlled in the range of 1014―1019cm−3by varying the annealing temperature and duration. As another example, the obtained photovoltaic properties in heterojunction solar cells that were fabricated by depositing n-(Ga0.975Al0.025)2O3thin films on p-Cu2O:Na sheets by PLD remained constant asPwas increased to approximately 1×1016cm−3, and then they decreased significantly asPwas increased further. The reduction of the obtained photovoltaic properties in heterojunction solar cells fabricated using Cu2O:Na sheets with aPabove about 1.4×1016cm−3was attributed mainly to decreases of both the depletion layer width and the diffusion length.