The Effect of Metal in MoOx/Metal/MoOx Anode on Open Circuit Voltage in Organic Photovoltaic Cells

Abstract

Archetypal photovoltaic cells are fabricated in order to elucidate the effect of a metal embedded in a semitransparent trilayer electrode on photovoltage. A series of electrodes are formed by thermal deposition of MoO x , metal and MoO x layers, in said succession (MoO x ¼ substoichometric molybdenum trioxide, metal ¼ Au, Cu, Ag, Al, In, Mg, Yb). The parameters of the Schottkytype cells consisting of thus made bottom anode, a subphthalocyanine boron chloride (SubPc) photoabsorber and a bilayer LiF/Al top cathode are measured and compared to those of the reference cell with an ITO/MoO x anode. Photovoltage does not correlate with the work function of a metal in the anode, while the photocurrent is inversely proportional to the anode sheet resistance. The highest efficiency is achieved with the silver interlayer, but the reference cell with ITO outperforms any cell with a trilayer anode. Then, comparison is made with a series of cells, in which the metal (Cr, Ni, Ag, Al, and Ta) in anode is deposited by a dc magnetron sputtering. In these cells, the photovoltage rises monotonically with the metal work function. Magnetron sputtered nickel in the anode provides the best cell performance, closely approaching that of the reference cell.

Developing efficient small molecule-based organic photo-couplers by optimizing the cathode interfacial layer in the photodetector

“…35,36 Application of a cathode interlayer prevents the formation of the recombination center at the interface by blocking the diffusion of hot metal atoms during the thermal evaporation process and suppressing the dark current density as well. 35–39…”

“…35,36 Application of a cathode interlayer prevents the formation of the recombination center at the interface by blocking the diffusion of hot metal atoms during the thermal evaporation process and suppressing the dark current density as well. [35][36][37][38][39] As visualized in Fig. S1 (ESI †), an efficient OPC composed of structurally isolated tandem OLED and OPD is investigated in this study.…”