High voltage hybrid organic photovoltaics using a zinc oxide acceptor and a subphthalocyanine donor

Abstract

We demonstrate hybrid organic photovoltaic (HOPV) bilayer devices with very high open circuit voltages (VOC) of 1.18 V based on a sol-gel processed zinc oxide (ZnO) acceptor and a vacuum deposited boron subphthalocyanine chloride (SubPc) donor layer. X-ray photoelectron spectroscopy (XPS) and Kelvin Probe (KP) measurements of the ZnO/SubPc interface show that the ZnO preparation conditions have a significant impact on the film composition and the electronic properties of the interface, in particular the work function and interface gap energy. Low temperature processing at 120 °C resulted in a ZnO work function of 3.20 eV and the highest VOC of 1.18 V, a consequence of the increased interface gap energy.

Buffer-Free Inverted Photovoltaic Cells with Hybrid C60 /CuI Heterojunction

“…In hybrid bulk heterojunctions, one organic component, for example, the fullerene derivative, is replaced by inorganic nanoparticles or quantum dots, while the other one remains organic in nature (polymer) . The hybrid devices with a classical (flat, non‐structured) heterojunction attract less attention currently, since their characteristics are generally inferior to those of fully organic congeners …”

Investigation of the Electrical Characteristics of Bilayer ZnO/In2O3 Thin-Film Transistors Fabricated by Solution Processing

“…This suggests that the band offset between ZnO and In 2 O 3 may cause charge transport in the bilayer structure. Given that ZnO has a lower Fermi level (approximately 3.2 eV) than that (approximately 4.3 eV) of In 2 O 3 [28,29], it is possible that electrons in the Fermi level of ZnO migrate to that of In 2 O 3 in the bilayer structure, as depicted in Figure 7a. In consequence, the electron migration from ZnO into In 2 O 3 will deplete the electrons near the surface of the underlying ZnO film and then the electron-depletion layer will be positively charged.…”

Thiadiazole Fused Subporphyrazines as Acceptors in Organic Photovoltaic Cells

“…[13,14] The preparation of the archetypal photovoltaic cell was similar to that previously reported. [18,19] The cell scheme was 'glass/ ITO/MoO x /SubPcH 12 /acceptor/Al', where MoO x is a 10 nm substoichiometric molybdenum trioxide layer (buffer/workfunction modifier, [1,[5][6][7][8]19] see Figure S1), acceptor = SubPzS 3 F 0 , SubPzS 2 F 4 , SubPzS 1 F 8 , SubPcF 12 (or C 60 , see text), and Al is an aluminum top cathode (40 nm). The thickness of a p-type layer (SubPcH 12 ) was 20 nm, the thickness of an n-type (acceptor) layer was 30 nm.…”

“…Parent compound, unsubstituted subphthalocyaninatoboron(III) chloride is routinely utilized as a donor in the devices containing molecular [5,6] or hybrid [7] heterojunctions, but can also serve as an acceptor in conjunction with the electronrich molecular materials, such as polyarenes or thiophenes. [8] It was recently shown that even without p/n junction subphthalocyanines give higher yields of free charge carriers upon photoexcitation than other molecular semiconductors.…”