Small molecule solution-processed bulk heterojunction solar cells with inverted structure using porphyrin donor

Abstract

Utilizing tetraethynyl porphyrin derivative (TE-Por) as a small molecule donor material, we fabricated a small molecule solution-processed bulk heterojunction (BHJ) solar cell with inverted structure, which exhibited 1.6% power conversion efficiency (JSC (short-circuit current) = 4.6 mA/cm2, VOC (open-circuit voltage) = 0.90 V, and FF (fill factor) = 0.39) in the device configuration indium tin oxide/TiOx (titanium sub-oxide)/[6,6]-phenyl-C61-butyric acid methyl ester:TE-Por (5:1)/MoOx (molybdenum sub-oxide)/Au under AM1.5 G illumination at 100 mW/cm2. Without encapsulation, the small molecule solution-processed inverted BHJ solar cell also showed remarkable durability to air, where it kept over 73% of its initial power conversion efficiency after storage for 28 days under ambient atmosphere in the dark.

Fabrication and characterization of P3HT:PCBM-based thin film organic solar cells with zinc phthalocyanine

“…The ZnPc was added as the third component for PCBM:P3HT solar cells. The polarity of charge collection is reversed from conventional devices in the inverted structure [22][23][24], which are expected to provide stable devices in air [25][26][27][28]. The photovoltaic mechanism and charge transfer were discussed on the basis of light-induced current density-voltage (J-V) curves and IPCE.…”

Fabrication and Characterization of PCBM: P3HT-based Thin-film Organic Solar Cells with Zinc Phthalocyanine and 1,8-Diiodooctane

“…1,8-diiodooctane (DIO) was also added to improve the photovoltaic properties [22,23]. The polarity of charge collection is reversed from conventional devices in the inverted structure [24][25][26], which are expected to provide stable devices in air [27][28][29][30]. The photovoltaic mechanism and an energy level diagram of the present solar cells were discussed on the basis of light-induced current density-voltage (J-V) curves and IPCE.…”

A combination of Al-doped ZnO and a conjugated polyelectrolyte interlayer for small molecule solution-processed solar cells with an inverted structure

“…In addition, the inverted architecture is known to be better compatible for production via printing processes. 9,[11][12][13] Interface engineering plays a key role in the formation of charge selective interfaces and is critical to the whole device performance and stability. However, it was difficult to investigate interface engineering in small molecule inverted solar cells due to two signicant reasons.…”

“…On the one hand, highly acidic poly (3,4-ethyl-enedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) used as the electron blocking layer and hole selective layer at the anode side resulted in decomposition of small molecules and hindered the selection of an electron transporting layer. 12 Recently, molybdenum sub-oxides (MoO x ) with high work functions (WFs), deposited by vacuum deposition, were demonstrated as promising alternatives to PEDOT:PSS. [11][12][13] On the other hand, although various stable low WF metal oxides, such as TiO x and ZnO, as the electron extraction layer in the cathode side have been widely applied for polymeric solar cells (PSCs) to improve the photovoltaic properties of devices, [14][15][16][17][18] some metal-oxide-based devices have intrinsic limitations including incomplete ligand removal, unbalanced charge carrier injection and transport, or inefficient electron-hole recombination, which result in poor control of the electronic surface properties, high contact resistance or surface recombination.…”