Influence of Shell Thickness and Surface Passivation on PbS/CdS Core/Shell Colloidal Quantum Dot Solar Cells

被引：130

作者：

Neo, Darren C. J. ^{[1
]}

Cheng, Cheng ^{[1
]}

Stranks, Samuel D. ^{[2
]}

Fairclough, Simon M. ^{[1
]}

Kim, Judy S. ^{[1
]}

Kirkland, Angus I. ^{[1
]}

Smith, Jason M. ^{[1
]}

Snaith, Henry J. ^{[2
]}

Assender, Hazel E. ^{[1
]}

Watt, Andrew A. R. ^{[1
]}

机构：

[1] Univ Oxford, Dept Mat, Oxford OX1 3PH, England

[2] Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England

来源：

CHEMISTRY OF MATERIALS | 2014年 / 26卷 / 13期

基金：

英国工程与自然科学研究理事会;

关键词：

NANOCRYSTAL SOLIDS; PBS NANOCRYSTALS; PHOTOVOLTAICS; RECOMBINATION; FABRICATION; SCATTERING; CHEMISTRY; PBSE/PBS; SELENIDE; QDS;

D O I：

10.1021/cm501595u

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Cation-exchange has been used to synthesize PbS/CdS core/shell colloidal quantum dots from PbS starting cores. These were then incorporated as the active material in solar cell test devices using a solution-based, air-ambient, layer-by-layer spin coating process. We show that core/shell colloidal quantum dots can replace their unshelled counterparts with a similar band gap as the active layer in a solar cell device, leading to an improvement in open circuit voltage from 0.42 to 0.66 V. This improvement is attributed to a reduction in recombination as a result of the passivating shell. However, this increase comes at the expense of short circuit current by creating a barrier for transport. To overcome this, we first optimize the shell thickness by varying the conditions for cation-exchange to form the thinnest shell layer possible that provides sufficient surface passivation. Next, ligand exchange with a combination of halide and bifunctional organic molecules is used in conjunction with the core/shell strategy. Power conversion efficiencies of 5.6 +/- 0.4% have been achieved with a simple heterojunction device architecture.

引用

页码：4004 / 4013

页数：10

共 68 条

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