Highly Efficient Inverted Polymer Solar Cells Using an Indium Gallium Zinc Oxide Interfacial Layer

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

“…We recorded the UPS profiles (Figure 3C) and UV‐Vis absorption spectra (Figure S2A) of the HTLs to determine their energy levels (ie, the highest occupied molecular orbital [HOMO] and lowest unoccupied molecular orbital [LUMO]). The energy associated with the HOMO level ( E HOMO ) can be estimated from the UPS profile of a sample using the following equation (Equation []) 6 : where W is the width of the UPS profile of the corresponding sample, 21.22 eV. The energy associated with the LUMO level ( E LUMO ) is the difference between E HOMO and the energy (optical) band gap (calculated by analyzing the UV‐Vis absorption spectra of the films) of the corresponding sample (Equation []) 6 …”

“…The energy associated with the HOMO level ( E HOMO ) can be estimated from the UPS profile of a sample using the following equation (Equation []) 6 : where W is the width of the UPS profile of the corresponding sample, 21.22 eV. The energy associated with the LUMO level ( E LUMO ) is the difference between E HOMO and the energy (optical) band gap (calculated by analyzing the UV‐Vis absorption spectra of the films) of the corresponding sample (Equation []) 6 where E g is the optical energy band gap of the corresponding sample.…”

“…Organic photovoltaics (OPVs) are potential for next‐generation photovoltaic (PV) technology due to their excellent qualities such as low weight, cheap cost, processability, mechanical flexibility, roll‐to‐roll printing capability, and semi‐transparency 1‐3 . In the last 30 years, OPV devices have been improved significantly through persistent efforts 4‐6 . For example, various donor and acceptor materials with synergic physicochemical properties have been employed, 7,8 and different organic and inorganic charge‐collecting interlayers (eg, electron transport layers 6 and hole transport layers [HTLs]) 9 are being developed.…”

“…[1][2][3] In the last 30 years, OPV devices have been improved significantly through persistent efforts. [4][5][6] For example, various donor and acceptor materials with synergic physicochemical properties have been employed, 7,8 and different organic and inorganic charge-collecting interlayers (eg, electron transport layers 6 and hole transport layers [HTLs]) 9 are being developed. Furthermore, the optimization of the thickness of the different layers of OPV devices has been intensively investigated.…”

“…Further, the material exhibited a significantly lower acidity (pH = 2.7) compared with the widely used PEDOT:PSS (pH = 1.6). Subsequently, we developed a poly(3-hexylthiophene) (P3HT): [6]-indene-C60 bisadduct (ICBA) active layer, and PPY:PSS (with optimized weight ratio between PPY and PSS) HTL-based OPV with a maximum PCE of 5.0% (11% higher than a PEDOT: PSS HTL-based OPV).…”