Relaxation of Electron Carriers in the Density of States of Nanocrystalline TiO2

被引:46
作者
Bertoluzzi, Luca [1 ]
Herraiz-Cardona, Isaac [1 ]
Gottesman, Ronen [2 ]
Zaban, Arie [2 ]
Bisquert, Juan [1 ]
机构
[1] Univ Jaume 1, Dept Fis, Photovolta & Optoelect Devices Grp, Castellon de La Plana 12071, Spain
[2] Bar Ilan Univ, Dept Chem, Inst Nanotechnol & Adv Mat, IL-52900 Ramat Gan, Israel
来源
JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2014年 / 5卷 / 04期
关键词
THIN SEMICONDUCTOR-FILMS; SURFACE-STATES; SOLAR; RECOMBINATION; MOBILITY; ANATASE; ORIGIN; WATER;
D O I
10.1021/jz4027584
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
Band gap localized states and surface states play a dominant role in the application of nanocrystalline metal oxides to photovoltaics and solar fuel production. Electrons injected in nanocrystalline TiO2 by voltage or photogeneration are mainly located in band gap states. Therefore, charging a nanoparticulate semiconductor network allows one to recover the density of states (DOS) in the energy axis. However, shallow traps remain in equilibrium with the conduction band electrons, while deep traps do not. We show that the characteristic peak of the apparent DOS mixes an exponential DOS and a monoenergetic surface state. A model that incorporates the trap's kinetics proves to be very efficient to assess the important parameters that determine both contributions via variation of charging rate. Contrary to the common theory, we demonstrate that the peculiar capacitance peak of nanocrystalline TiO2 can be mainly attributed, in some cases, to deep traps in the exponential distribution.
引用
收藏
页码:689 / 694
页数:6
相关论文
共 36 条
[11]   Theory of the impedance of charge transfer via surface states in dye-sensitized solar cells [J].
Bisquert, Juan .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 2010, 646 (1-2) :43-51
[12]   Beyond the quasistatic approximation: Impedance and capacitance of an exponential distribution of traps [J].
Bisquert, Juan .
PHYSICAL REVIEW B, 2008, 77 (23)
[13]   Spectroelectrochemical investigation of surface states in nanostructured TiO2 electrodes [J].
Boschloo, G ;
Fitzmaurice, D .
JOURNAL OF PHYSICAL CHEMISTRY B, 1999, 103 (12) :2228-2231
[14]   Sequential deposition as a route to high-performance perovskite-sensitized solar cells [J].
Burschka, Julian ;
Pellet, Norman ;
Moon, Soo-Jin ;
Humphry-Baker, Robin ;
Gao, Peng ;
Nazeeruddin, Mohammad K. ;
Graetzel, Michael .
NATURE, 2013, 499 (7458) :316-+
[15]   Investigation of the electronic transport properties of nanocrystalline particulate TiO2 electrodes by intensity-modulated photocurrent spectroscopy [J].
de Jongh, PE ;
Vanmaekelbergh, D .
JOURNAL OF PHYSICAL CHEMISTRY B, 1997, 101 (14) :2716-2722
[16]   ELECTROCHEMICAL MEASUREMENTS OF INTERFACE STATES AT THE GAAS-OXIDE INTERFACE [J].
FRESE, KW ;
MORRISON, SR .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1979, 126 (07) :1235-1241
[17]   ELECTROCHEMICAL PHOTOLYSIS OF WATER AT A SEMICONDUCTOR ELECTRODE [J].
FUJISHIMA, A ;
HONDA, K .
NATURE, 1972, 238 (5358) :37-+
[18]  
Fujishima A., 2000, J PHOTOCH PHOTOBIO C, V1, P1, DOI DOI 10.1016/S1389-5567(00)00002-2
[19]   Direct Imaging of the Recombination/Reduction Sites in Porous TiO2 Electrodes [J].
Gottesman, Ronen ;
Tirosh, Shay ;
Barad, Hannah-Noa ;
Zaban, Arie .
JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 2013, 4 (17) :2822-2828
[20]   A surface science perspective on TiO2 photocatalysis [J].
Henderson, Michael A. .
SURFACE SCIENCE REPORTS, 2011, 66 (6-7) :185-297