@Article{CL.2025.228.693,
AUTHOR = {Q. Fei, B. Jin, B. C. Jiang, J. S. Huang, L. Li},
TITLE = {Design and synthesis of diketopyrrolopyrrole-CdS hybrid nanostructures for enhanced photovoltaic applications},
JOURNAL = {Chalcogenide Letters},
VOLUME = {22},
YEAR = {2025},
NUMBER = {8},
PAGES = {693--705},
URL = {http://www.techscience.com/CL/v22n8/64839},
ISSN = {1584-8663},
ABSTRACT = {An innovative hybrid nanostructure composed of diketopyrrolopyrrole (DPP) oligomers and 
cadmium sulfide (CdS) nanoparticles was developed to enhance the efficiency of organic–
inorganic photovoltaic devices. The DPP-CdS hybrids were synthesized via a solution-phase 
mixing method, resulting in uniform nanoparticle dispersion along polymer fibrils and 
strong interfacial coupling. Structural characterization confirmed the coexistence of 
crystalline CdS domains and partially ordered DPP phases, while spectroscopic analyses 
indicated notable redshifts and band broadening, evidencing electronic interactions at the 
interface. The hybrid material displayed significantly broadened light absorption across the 
400–700 nm range and an optimized optical bandgap of ~1.92 eV. When implemented in 
inverted bulk heterojunction solar cells (ITO/PEDOT:PSS/DPP-CdS/PC<sub>71</sub>BM/Al), the 
active layer enabled a short-circuit current density of 11.3 mA/cm<sup>²</sup>, open-circuit voltage of 
0.82 V, and a power conversion efficiency (PCE) of 5.93%—more than double the PCEs of 
devices with only DPP (2.61%) or CdS (1.35%). External quantum efficiency exceeded 60% 
at peak wavelengths, confirming efficient exciton generation and charge extraction. 
Furthermore, electrochemical impedance spectroscopy showed a reduced charge transfer 
resistance of 238 Ω, while transient photovoltage measurements revealed an extended 
carrier lifetime of 6.10 μs, indicating minimized recombination losses. These improvements 
are attributed to favorable energy level alignment, enhanced morphology, and interfacial 
engineering in the DPP-CdS hybrids. This work demonstrates the potential of combining 
conjugated organics with tailored inorganic nanostructures to overcome current 
performance limitations in hybrid photovoltaics and provides a scalable strategy for nextgeneration
 solar energy materials. },
DOI = {10.15251/CL.2025.228.693}
}