Comparative degradation analysis of V2O5, MoO3 and their stacks as hole transport layers in high-efficiency inverted polymer solar cells

Saeed

Macromol. Rapid Commun.

et al. 2022

Organic indoor photovoltaics (IPVs) are attractive energy harvesting devices for low-power consumption electronic devices and the Internet of Things (IoTs) owing to their properties such as being lightweight, semitransparent, having multicoloring capability, and flexibility. It is important to match the absorption range of photoactive materials with the emission spectra of indoor light sources that have a visible range of 400-700 nm for IPVs to provide sustainable, high-power density. To this end, benzo[1,2-b:4,5-b′]dithiophene-based homopolymer (PBDTT) is synthesized as a polymer donor, which is a classical material that has a wide bandgap with a deep highest occupied molecular orbitals (HOMO) level, and a series of random copolymers by incorporating thieno[3,4-c]pyrrole-4,6,-dione (TPD) as a weak electron acceptor unit in PBDTT. The composition of the TPD unit is varied to fine tune the absorption range of the polymers; the polymer containing 70% TPD (B30T70) perfectly covers the entire range of indoor lamps such as light-emitting diodes (LEDs) and fluorescent lamp (FL). Consequently, B30T70 shows a dramatic enhancement of the power conversion efficiency (PCE) from 1-sun (PCE: 6.0%) to the indoor environment (PCE: 18.3%) when fabricating organic IPVs by blending with PC 71 BM. The simple, easy molecular design guidelines are suggested to develop photoactive materials for efficient organic IPVs.

Section: Resultsmentioning

confidence: 99%

Revisiting the Classical Wide‐Bandgap HOMO and Random Copolymers for Indoor Artificial Light Photovoltaics

Saeed

Macromol. Rapid Commun.

et al. 2022

Intl J of Energy Research

“…Thus far, both inorganic and organic p‐type semiconductors have been utilized as HTL materials for OPV devices. Initially, p‐type inorganic semiconductors, such as molybdenum trioxide, 17 iron (II, III) oxide, 18 molybdenum disulfide, 19 and tungsten trioxide, 20 were used as the HTLs of different active‐layer‐based OPV devices owing to their extremely high transmission, environmental stability, high hole extraction ability, desirable WF, and electron‐obstructing capability. However, these inorganic semiconductors were deposited onto the anode layer via vacuum deposition, which is not favorable for commercialization.…”

Section: Introductionmentioning

confidence: 99%

Polystyrene‐sulfonate‐doped polypyrrole: Low‐cost hole transport material for developing highly efficient organic solar cells

Biswas

Lee

You

et al. 2022

Summary The hole transport layer (HTL) is a vital part in an organic photovoltaic (OPV) device for improving hole extraction ability. The HTL of OPV devices is typically prepared using poly (3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). However, it presents several disadvantages, including causing deterioration of the active layers, exhibiting sensitivity to ultraviolet radiation, and possessing a short lifespan. Hence, focus has increased on alternative p‐type semiconductors with improved environmental stability, easier processing, and higher conductivity. In this study, we prepare water‐stable, low‐cost, and low‐acidity PSS‐doped polypyrrole (PPY) with varying PSS concentrations for use as the HTL in OPV devices. The films formed using PPY:PSS exhibit an extremely high transmittance within the visible range. The PPY:PSS HTL‐based OPV may reach to highest power conversion efficiency of 5.0% (ie, 11% higher than a PEDOT:PSS‐based one) when using an optimal PSS concentration in PPY.

IEEE J. Electron Devices Soc.

“…Several buffer layers combined with a low work function metal electrodes have been reported to improve the performance and lifetime of organic solar cells. In iOSCs, as hole transport layer (HTL) are used commonly vanadium oxide (V 2 O 5 ) [6], [7], molybdenum oxide (MoO 3 ) [8], [9] and nickel oxide (NiO) [10], [11]. As electron transport layer (ETL) are used commonly PFN [12], [13], zinc oxide (ZnO) [14], [15] and titanium oxide (TiO x ) [16], [17].…”

Section: Introductionmentioning

confidence: 99%

Solution-Processed Small Molecule Inverted Solar Cells: Impact of Electron Transport Layers

Ramirez-Como

Balderrama

Sánchez

et al. 2022

Self Cite

In this work, the use of poly [(9,9-bis (30-(N,N-dimethylamino) propyl) -2,7-fluorene)alt-2,7-(9,9-dioctylfluorene) (PFN) as electron transport layer (ETL) in inverted small molecule solar cells (SM-iOSCs) is analyzed. The optical and electrical characteristics obtained are compared with those obtained for similar SM-iOSCs where the ETL was zinc oxide. The p-DTS(FBTTh 2 ) 2 and PC 70 BM materials are used as donor and acceptor in the bulk heterojunction active layer, respectively for all devices. The photovoltaic devices exhibited a power conversion efficiency of 6.75% under 1 sun illumination. Impedance measurements were used to understand the causes that dominate the performance of the devices. We found that the loss resistance is governed by the PFN layer, which results in a lower fill factor value. Studies of atomic force microscopy, external quantum efficiency, and absorption UV-vis on the active layer have been performed to understand the effects of the charge transport dynamics on the performance of the devices.INDEX TERMS Buffer layers, dependence light intensity, electron transport layer, impedance spectroscopy, organic solar cells, p-DTS(FBTTh 2 ) 2 :PC 70 BM solar cells, PFN ETL, Solution-processed small molecule, ZnO ETL.