Improved Visible Light Harvesting of WO3 by Incorporation of Sulfur or Iodine: A Tale of Two Impurities
Improved Visible Light Harvesting of WO3 by Incorporation of Sulfur or Iodine: A Tale of Two Impurities
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DOI：
10.1021/cm403969r
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发表时间：
2014-02
影响因子：
8.6
通讯作者：
A. Rettie;K. Klavetter;Jung‐Fu Lin;A. Dolocan;H. Celio;Ashioma Ishiekwene;Heather L. Bolton;Kristen N.
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文献类型：
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作者：
A. Rettie;K. Klavetter;Jung‐Fu Lin;A. Dolocan;H. Celio;Ashioma Ishiekwene;Heather L. Bolton;Kristen N.
本文报道了在单斜相三氧化钨（S：WO3或I：WO3）中引入硫或碘，以提高其可见光捕获能力。薄膜合成喷雾热解与硫化铵或碘添加到水性WO3前体溶液。吸收光谱的红移与S和I的掺入（从2.7至2.6和2.1 eV分别），可能是由于形成的intragap杂质带。S：WO3样品在低S浓度下表现出增强的光电化学（PEC）性能，但这很快随着S含量的增加而恶化。入射光子转换效率（IPCE）数据显示，这种初始改善是由更长波长下的收集效率改善驱动的。相反，光电流下降，在所有水平的I此外。这些薄膜的IPCE测量结果表明，在较长的波长下，效率仅略有增加，表明额外吸收的光子并没有贡献硅。
We report the incorporation of sulfur or iodine into monoclinic tungsten trioxide (S:WO3 or I:WO3 respectively), with the aim to improve its visible light-harvesting ability. Films were synthesized by spray pyrolysis with either ammonium sulfide or iodide added to the aqueous WO3 precursor solutions. Red shifts of the absorption spectra were observed with S and I incorporation (from ∼2.7 to 2.6 and 2.1 eV respectively), likely due to the formation of intragap impurity bands. S:WO3 samples exhibited enhanced photoelectrochemical (PEC) performance at low S concentrations, but this quickly deteriorated with increasing S content. Incident photon conversion efficiency (IPCE) data showed that this initial improvement was driven by improved collection efficiency at longer wavelengths. Conversely, photocurrent decreased at all levels of I addition. IPCE measurements for these films showed only a marginal increase in efficiency at longer wavelengths, indicating that the extra absorbed photons did not contribute si...