Influence of reaction conditions on the properties of solution-processed Cu2ZnSnS4 nanocrystals
Influence of reaction conditions on the properties of solution-processed Cu2ZnSnS4 nanocrystals
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DOI：
10.1088/2053-1591/1/4/045040
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发表时间：
2014-12-01
影响因子：
2.3
通讯作者：
Beattie, Neil S.
中科院分区：
文献类型：
--
作者：
Qu, Yongtao;Zoppi, Guillaume;Beattie, Neil S.
通过热注入硫到金属前体溶液中制备了Cu 2 ZnSnS 4纳米晶。通过仔细控制反应条件，可以控制纳米晶体的元素组成，使得它们适合于地球丰富的光伏吸收剂。当反应温度从195 ℃增加到240 ℃时，纳米晶体的能带隙从1.65 eV减小到1.39 eV。这种变化是由混合纤锌矿-锌黄锡矿相在较低的反应温度和第二相Cu 2SnS 3在较高的温度下的识别。此外，纤锌矿结构的存在关键取决于反应冷却速率。还发现反应时间对纳米晶体具有强烈的影响，随着反应的进行，纳米晶体变得越来越贫铜和富锌。随着反应时间从15 min增加到60 min，能带隙从1.42 eV增加到1.84 eV。这种变化进行了讨论的样品掺杂。结果表明，优化反应条件对制备高质量Cu 2 ZnSnS 4纳米晶具有重要意义。
Cu2ZnSnS4 nanocrystals were fabricated by hot injection of sulphur into a solution of metallic precursors. By careful control of the reaction conditions it was possible to control the elemental composition of the nanocrystals such that they are suitable for earth abundant photovoltaic absorbers. When the reaction temperature increased from 195 degrees C to 240 degrees C the energy band gap of the nanocrystals decreased from 1.65 eV to 1.39 eV. This variation is explained by the identification of a mixed wurtzite-kesterite phase at lower reaction temperatures and secondary phase Cu2SnS3 at higher temperatures. Moreover, the existence of wurtzite structure depends critically on the reaction cooling rate. The reaction time was also found to have a strong effect on the nanocrystals which became increasingly copper poor and zinc rich as the reaction evolved. As the reaction time increase from 15 min to 60 min, the energy band gap increased from 1.42 eV to 1.84 eV. This variation is discussed in terms of the sample doping. The results demonstrate the importance of optimizing the reaction conditions to produce high quality Cu2ZnSnS4 nanocrystals.