Tunable Photoelectrochemical Properties of Chalcopyrite AgInS2 Nanoparticles Size-Controlled with a Photoetching Technique

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• 作者：Tsukasa Torimoto ; Masaki Tada ; Meilin Dai ; Tatsuya Kameyama ; Shushi Suzuki ; Susumu Kuwabata
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：October 18, 2012
• 年：2012
• 卷：116
• 期：41
• 页码：21895-21902
• 全文大小：384K
• 年卷期：v.116,no.41(October 18, 2012)
• ISSN：1932-7455

文摘

Size-selective photoetching enabled precise size control of chalcopyrite AgInS₂ nanoparticles in a basic aqueous solution containing ammonia by selecting the wavelength of monochromatic irradiation light in the range between 650 and 520 nm. The energy gap of the photoetched particles was enlarged from 1.8 to 2.4 eV with a decrease in particle size from 5.1 to 2.7 nm due to the quantum size effect, while the crystal structure and chemical composition of the particles were unchanged after the photoetching processes. AgInS₂ nanoparticle-immobilized electrodes exhibited an anodic photocurrent similar to that of n-type semiconductors, the onset potential of which was negatively shifted with a decrease in particle size. Potentials of the conduction band edge (E_CB) and the valence band edge (E_VB) of AgInS₂ nanoparticles were estimated from their photoelectrochemical measurements, and they exhibited remarkable size dependence: with a decrease in particle size from 5.1 to 2.7 nm, E_CB was shifted negatively from 鈭?.6 to 鈭?.0 V vs Ag/AgCl, accompanied by a positive shift of E_VB from 1.3 to 1.7 V vs Ag/AgCl.