Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 21: Transport properties I

HL 21.3: Talk

Tuesday, March 28, 2006, 17:00–17:15, BEY 118

Surface photovoltage for characterization of porous semiconductors — •Thomas Dittrich¹, Iván Mora-Seró², Germà García-Belmonte², and Juan Bisquert² — ¹Hahn-Meitner-Institut, Glienicker Str. 100, 14109 Berlin, Germany — ²Departament de Ciències Experimentals, Universitat Jaume I, E-12080 Castelló, Spain

The surface photovoltage method is a locally sensitive technique with respect to even extremely short charge separation lengths. In conventional semiconductors, the charge separation length is given mainly by the thickness of the space charge region. The situation may change for porous semiconductors. In such systems, a time dependent development of the charge separation length from an initial value, given also by the duration time of the laser pulse, up to a screening length (Debye screening length in homogeneous media) has been observed and described by a diffusion model. The processes of diffusion and screening will be discussed on the example of porous TiO_2 layers sensitized with dye molecules.