Bulk heterojunction photovoltaic cells based on vacuum evaporated cadmium sulfide–phthalocyanine hybrid structures

Abstract

Bulk heterojunction (BHJ) photovoltaic (PV) cells have been prepared by vacuum co-deposition of inorganic cadmium sulfide (CdS) and organic zinc phthalocyanine (PcZn) materials. Characteristics of the BHJ cells were compared with the cells based on vacuum evaporated bilayer CdS/PcZn heterojunctions, and it was found that the BHJ structure possesses higher PV performance due to higher interface area at which excitons can dissociate. Variation of the component ratio in the BHJ devices and comparison of their photocurrent spectra allowed us to distinguish the contribution of CdS, CdS/PcZn interface and PcZn to the PV response. The mechanism of charge transport was attributed to the model of space-charge-limited current with traps; however, the concentration of traps was different in the bilayer and BHJ structures.

Lighting porphyrins and phthalocyanines for molecular photovoltaics

“…CdS). 78 However, the longer exciton diffusion length of C 60 (i.e., B40 nm) with regard to other electronacceptors makes fullerene a molecule of choice for the optimization of PHJ cells. After a former report on the photovoltaic properties of ITO/C 60 /H 2 Pc/Au sandwich solar cells showing energy conversion yields of 0.03% when illuminated by white light, 79 a PCE of 3.6% was obtained with vacuum-deposited Cu(II)Pc/C 60 PHJ photovoltaic cells incorporating a layer of BCP, and also a modified ITO anode, which was covered by a thick film of 3,4-polyethylenedioxythiophene : polystyrenesulfonate (PEDOT : PSS) in order to planarize the rough ITO surface.…”

Structural, Optical, and Electrical Properties of in Situ Synthesized ZnO–CuPc Nanocomposites

“…Hybrid structures are employed as simple planar multilayer junctions, , disordered bulk heterojunctions, , (where the two materials are mixed to form composite materials), ordered bulk heterojunctions , and dye-sensitized solar cell . Several methods have been employed to form hybrid composite materials like electrochemical deposition, coevaporation, simple physical mixing of the two materials in solution, ball milling, etc.…”

“…Hybrid structures are employed as simple planar multilayer junctions, , disordered bulk heterojunctions, , (where the two materials are mixed to form composite materials), ordered bulk heterojunctions , and dye-sensitized solar cell . Several methods have been employed to form hybrid composite materials like electrochemical deposition, coevaporation, simple physical mixing of the two materials in solution, ball milling, etc. In the above-mentioned hybrid structures the extent to which these materials can mix and form a composite plays a significant role since efficient charge separation, and transport is needed at the inorganic (acceptor)–organic (donor) interface .…”

Growth of CdS thin films and nanowires for flexible photoelectrochemical cells

“…There have been many CdS deposition techniques including vacuum evaporation (Grynko et al, 2009), RF sputtering (Akkad and Ashour, 2009), chemical vapor deposition (Jones et al, 2009) and molecular beam epitaxy (Ueta et al, 2000). All these methods require special tools, and therefore their manufacturing cost is high.…”