Analysis of deep levels in a phenylenevinylene polymer by transient capacitance methods

Transient capacitance methods were applied to the depletion region of an ab rupt asymmetric n(+) -p junction of silicon and unintentionally doped poly[ 2-methoxy, 5 ethyl (2' hexyloxy) paraphenylenevinylene] (MEH-PPV). Studies in the temperature range 100-300 K show the presence of a majority-carrier trap at 1.0 eV and two minority traps at 0.7 and 1.3 eV, respectively. Ther e is an indication for more levels for which the activation energy could no t be determined. Furthermore, admittance data reveal a bulk activation ener gy for conduction of 0.12 eV, suggesting the presence of an additional shal low acceptor state. (C) 1999 American Institute of Physics. [S0003-6951(99) 02308-6].