We determine the influence of substitutional defects on perovskite quantum dots through experimental and theoretical investigations. Substitutional defects were introduced by trivalent dopants (In, Sb, and Bi) in CsPbBr₃ by ligand-assisted reprecipitation. We show that the photoluminescence (PL) emission peak shifts toward shorter wavelengths when doping concentrations are increased. Trivalent metal-doped CsPbBr₃ enhanced the PL quantum yield (~10%) and air stability (over 10 days). Our findings provide new insights into the influence of substitutional defects on substituted CsPbBr₃ that underpin their physical properties.

Fiber-shaped dye-sensitized solar cells (FDSSCs) with flexibility, weavablity, and wearability have attracted intense scientific interest and development in recent years due to their low cost, simple fabrication, and environmentally friendly operation. Since the Grätzel group used the organic radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as the redox system in dye-sensitized solar cells (DSSCs) in 2008, TEMPO has been utilized as an electrolyte to further improve power conversion efficiency (PCE) of solar cells. Hence, the TEMPO with high catalyst oxidant characteristics was developed as a hybrid solid-state electrolyte having high conductivity and stability structure by being integrated with a lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) film for FDSSCs. The optimized 4-Oxo TEMPO (OX) based solid-state FDSSC (SS-FDSSC) showed the PCE of up to 6%, which was improved by 34.2% compared to that of the reference device with 4.47%. The OX-enhanced SS-FDSSCs reduced a series resistance (R_s) resulting in effective electron extraction with improved short-circuit current density (J_SC), while increasing a shunt resistance (R_sh) to prevent the recombination of photo-excited electrons. The result is an improvement in a fill factor (FF) and consequently a higher value for the PCE.

Fiber-shaped solar cells (FSCs) with flexibility, wearability, and wearability have emerged as a topic of intensive interest and development in recent years. Although the development of this material is still in its early stages, bacteriophage-metallic nanostructures, which exhibit prominent localized surface plasmon resonance (LSPR) properties, are one such material that has been utilized to further improve the power conversion efficiency (PCE) of solar cells. This study confirmed that fiber-shaped dye-sensitized solar cells (FDSSCs) enhanced by silver nanoparticles-embedded M13 bacteriophage (Ag@M13) can be developed as solar cell devices with better PCE than the solar cells without them. The PCE of FDSSCs was improved by adding the Ag@M13 into an iodine species (I⁻/I₃⁻) based electrolyte, which is used for redox couple reactions. The optimized Ag@M13 enhanced FDSSC showed a PCE of up to 5.80%, which was improved by 16.7% compared to that of the reference device with 4.97%.

Plasmonic nanostructures, which exhibit notable localized surface plasmon resonance (LSPR) properties, are a promising approach for improving the efficiency of fiber‐shaped dye‐sensitized solar cells (FDSSCs) and flexible organic light‐emitting diodes (FOLEDs). Herein, novel plasmonic nanostructure is successfully synthesized via the self‐densification of gold nanoparticles (Au NPs) onto a genetically engineered M13 bacteriophage template. The synthesized Au NP‐M13 bio‐nanostructure show extraordinary gap‐plasmon effects and significantly enhanced LSPR properties compared to randomly dispersed Au NPs for both solid‐state FDSSCs (SS‐FDSSCs) and FOLEDs. Briefly, a power conversion efficiency (PCE) increment of 40.7% is recorded for the Au metallic NPs‐anchored M13 bacteriophage (Au NPs‐M13) enhanced SS‐FDSSCs; whereas an external quantum efficiency (EQE) increment of 47.2% is achieved for the Au NPs‐M13 enhanced FOLEDs.