Deep-level transient spectroscopy of TiO2/CuInS2 heterojunctions

Deep-level transient spectroscopy of TiO2/CuInS2 heterojunctions

Nanu, M.
Boulch, F.
Schoonman, J.
Goossens, A.

Applied Sciences

DelftChemTech

2005-12-07

Deep-level transient spectroscopy (DLTS) has been used to measure the concentration and energy position of deep electronic states in CuInS2. Flat TiO2?CuInS2 heterojunctions as well as TiO2-CuInS2 nanocomposites have been investigated. Subband-gap electronic states in CuInS2 films are mostly due to antisite point defects and vacancies. Substitution of indium with copper, CuInII, leads to an acceptor state 0.15 eV above the valence band, while copper vacancies, VCuI, are acceptor states at 0.1 eV. Furthermore, indium on a copper position, InCu?, yields a donor state at 0.07 eV below the conduction band, while sulphur vacancies are donor states at 0.0 = eV. With DLTS, these states are indeed found. For flat configurations, VCuI are the dominant acceptors with a concentration of 1.83×1017?cm?3. In contrast for nanocomposites CuInII are the dominant acceptors having a concentration of 6.7×1017?cm?3. We conclude that the concentration of antisite defects in nanocomposite CuInS2 is significantly higher than that in flat films of CuInS2.

deep level transient spectroscopy
titanium compounds
copper compounds
indium compounds
ternary semiconductors
semiconductor heterojunctions
nanocomposites
vacancies (crystal)
impurity states
valence bands
conduction bands

http://resolver.tudelft.nl/uuid:9370a88b-dbbc-4e65-bc2d-7e1042b7f21a

https://doi.org/10.1063/1.2140611

American Institute of Physics

0003-6951

http://link.aip.org/link/APPLAB/v87/i24/p242103/s1

Applied Physics Letters, 87 (24), 2005

Institutional Repository

journal article

(c) 2005 The Author(s); American Institute of Physics