Understanding and removing surface states limiting charge transport in TiO2 nanowire arrays for enhanced optoelectronic device performance
- Soochow Univ. (China)
- Northern Illinois Univ., DeKalb, IL (United States)
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
Charge transport within electrode materials plays a key role in determining the optoelectronic device performance. Aligned single-crystal TiO2 nanowire arrays offer an ideal electron transport path and are expected to have higher electron mobility. Unfortunately, their transport is found not to be superior to that in nanoparticle films. Here we show that the low electron transport in rutile TiO2 nanowires is mainly caused by surface traps in relatively deep energy levels, which cannot be removed by conventional approaches, such as oxygen annealing treatment. Moreover, we demonstrate an effective wet-chemistry approach to minimize these trap states, leading to over 20-fold enhancement in electron diffusion coefficient and 62% improvement in solar cell performance. On the basis of our results, the potential of TiO2 NWs can be developed and well-utilized, which is significantly important for their practical applications.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1242682
- Report Number(s):
- NREL-JA-5900-66161; MainId:16876; UUID:66ef7464-f0ea-e511-97db-d89d67132a6d; MainAdminID:5354
- Journal Information:
- Chemical Science, Vol. 7, Issue 3; Related Information: Chemical Science; ISSN 2041-6520
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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