Rectification effects based on the p-n junction of poly[γ- (β-N-carbazolylethyl) -L-glutamate]— 2,4,7-trinitrofluorenone systems

Publisher Website
Google Scholar
Abstract
In the dark and under illumination, it has been found that rectification effects in an organic photoconductor system are attributable to a p‐n junction barrier. This junction was accomplished by a doping process similar to one used in inorganic semiconductors. The p‐n junction barrier was made by immersing a poly[γ‐ (β‐N‐carbazolylethyl) ‐L‐glutamate] (PCLG) film in either benzene or a methylethylketone solution of 2,4,7‐trinitrofluorenone (TNF), since both benzene and methylethylketone are poor solvents for PCLG and are suitable solvents for TNF. PCLG and PCLG doped with TNF behave as p‐type and n‐type organic semiconductors, respectively, and a p‐n junction with a continuous interface can be accomplished in the sandwich structure system of In2O3//PCLG/PCLG‐TNF complex//Au. In this sample, rectification effects both in the dark and under illumination have been observed to be in good agreement with a theoretical equation of the p‐n junction for inorganic semiconductors. However, the potential drop across the p‐n junction barrier is depressed, being much smaller than the voltage applied externally to the photocell because of the remarkably high electrical resistivities of PCLG and the PCLG‐TNF complex. Furthermore, even without an applied field—that is, with a short circuit—the photovoltaic current has been observed and attributed to the junction barrier. On the other hand, in the In2O3//PCLG//Au and In2O3//PCLG‐TNF complex//Au systems it has been found that neither dark currents nor photocurrents attributable to a p‐n junction are observed.

This publication has 23 references indexed in Scilit: