P.K. Bhatnagar

Ga40Se60: A material for photovoltaic applications

Abstract Literature survey shows that Ga–Se material can be useful for photovoltaic applications. A proper heterostructure can be a promising replacement of conventional MOS solar cells. M–Ga 40 Se 60 cell structure has been fabricated and characterized.

Barrier height reduction due to metal wave function penetration in MOS solar cells

Abstract It has been shown from quantum mechanical considerations that the metal wave function penetrates into the oxide and reduces the barrier height considerably in tunnel MOS structures. This results in an increase in the majority carrier current and reduces the open circuit voltage of the MOS solar cell.

Self-trapping mechanism in green phosphorescent dye-doped polymer light-emitting diodes

The mechanism for exciting electroluminescence (EL) in a green phosphorescent dye, iridium(III)tris(2-(4-tolyl)pyridinato-N,C2) (Ir(mppy)3), doped in a host blue-emitting conducting polymer, poly[9,9-di-n-hexyl-fluorenyl-2,7-diyl] (PFO), has been studied. Photoluminescence measurements have been made on PFO/Ir(mppy)3 (0–12%) composites to rule out the possibility of singlet exciton energy transfer from the host polymer to the green dye. EL measurements have also been made to study the behavior of the composites in the presence of dc bias. The dominant mechanism for energy transfer from PFO to Ir(mppy)3 is found to be self-trapping of the charge carriers in the dye molecules, due to the extremely low LUMO and high HOMO levels as compared with PFO, thereby producing EL in the green region.