n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells
n-Type Transition Metal Oxide as a Hole Extraction Layer in PbS Quantum Dot Solar Cells
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DOI：
10.1021/nl2015729
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发表时间：
2011-08-01
期刊：
影响因子：
10.8
通讯作者：
Beard, Matthew C.
中科院分区：
文献类型：
--
作者：
Gao, Jianbo;Perkins, Craig L.;Beard, Matthew C.
由氧化钼（MoOx）和氧化钒（V2 Ox）组成的n型过渡金属氧化物（TMO）被用作异质结ZnO/PbS量子点太阳能电池（QDSC）中的有效空穴提取层（HEL）。报道了基于MoOx HEL的4.4%NH3认证的器件，其中Al作为背接触材料，与Au直接接触PbS量子点（QD）层的情况相比，效率提高了65%以上。我们发现空穴提取层的作用机制是在MoOx和PbS界面处形成的偶极子，增强能带弯曲，以允许MoOx从PbS层的价带有效地提取空穴。通过MoOx层中的浅隙态，载流子向金属阳极的传输可能得到增强。
The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoOx) and vanadium oxide (V2Ox) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoOx HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the case of Au contacting the PbS quantum dot (QD) layer directly. We find the acting mechanism of the hole extraction layer to be a dipole formed at the MoOx and PbS interface enhancing band bending to allow efficient hole extraction from the valence band of the PbS layer by MoOx. The carrier transport to the metal anode is likely enhanced through shallow gap states in the MoOx layer.