THE ROLE OF SPACE-CHARGE-LIMITED-CURRENT CONDUCTION IN EVALUATION OF THE ELECTRICAL-PROPERTIES OF THIN CU2O FILMS

Space-charge-limited-current conduction is the dominant charge transport mechanism in electrodeposited films of cuprous oxide; the measurement of current-voltage characteristic and temperature dependence of conductivity, while charge transport is space-charge limited, is used to evaluate the electrical parameters of the films. From these measurements and the measurement of the material band gap and dielectric constant, the energy-band diagram of Cu2O films has been determined for the first time. An optoelectronic band gap of 2.0 eV and a dielectric constant of 8.8 is measured for these films. The hole mobility in a sample with a resistivity of 1.1 X 10(11) OMEGA cm is measured to be 8.7 cm2/V s. The conductivity of this sample is controlled by an acceptor-type deep level (0.54 eV above valence band) with a concentration of 6.65 X 10(14) cm-3 which is compensated with a donor-type level (0.92 eV below conduction band) having a concentration of 6.64 X 10(14) cm-3.