V.V. Travkin, E.Y. Gudkov, P.A. Luchnikov, А.А. Nazarenсo

In this work the dependence of thermal annealing and orientation phthalocyanine sub-layer on the performance of thin-film organic photoconvertor prototypes based on planar heterojunction «boron chloride subphthalocyanine (SubPc) / fullerene (C60)» are demonstrated. Thin films of organic compounds and top aluminum contacts are deposited by thermal evaporation (and magnetron sputtering especially for metal) technique in high vacuum (~ 10-4 Ра) chamber from quartz and tungsten crucibles respectively on the flexible poly(ethylene)terephthalate (PET) and rigid glass substrates both covered with transparent conductive indium-tin oxide (ITO) layer. The current-voltage characteristics of samples under dark and illumination, in air and argon are measured. We made six different sample series: with thermal-annealed or non-annealed SubPc-layers both on glass and PET substrates (thermal evaporated top contacts); with non-annealed SubPc-layer deposited on preformed indium chloride phthalocyanine (InClPc) ultra-thin 5 nm sublayer with both thermal and magnetron inflicted top contacts on PET. It was found that thermal annealing at 90 oC of SubPc-layer deposited on the glass substrates leads to significant enhancement of prototype performance. For example, open circuit voltage Voc and short circuit current density Jsc also increases tenfold, while photo-conversion efficiency - up to fifty times from 0,004 to 0,19 % due to SubPc-layer crystallization and increasing the heterojunction roughness. Yet, when SubPc-layer deposited on flexible substrate undergoes to thermal anneal procedure then prototype-s photo-conversion efficiency falls from 0,78 to 0,26 % because of interface ITO-SubPc degradation by swelling ITO-layer. Insertion an ultra-thin InClPc orientation sub-layer leads to rise photo-conversion efficiency from 0,004 to 0,06 % that-s why sub-layer also results in crystallization of deposited SubPc-layer. The important fact is that magnetron sputtered top aluminum contact in comparison with thermal evaporated significantly reduces Jsc (up to 2 times). When all samples were exposed in air after argon, their Jsc and fill-factor had reduced.