Akademik Veri Yönetim Sistemi
ACS FALL 2025, Washington, Amerika Birleşik Devletleri, 17 - 21 Ağustos 2025, (Yayınlanmadı)
Photovoltaic devices generate electricity by absorbing sunlight and creating electron-hole pairs within a semiconductor. The Shockley-Queisser limit sets a 33% maximum efficiency for standard single junction cells, primarily limited by thermalization losses where excess photon energy is dissipated as heat rather than contributing to useful charge generation. Quantum-enhanced approaches like multiple exciton generation (MEG) can overcome this by creating multiple electron-hole pairs from single high-energy photons, potentially boosting efficiency beyond classical limits through nanoscale material engineering. It is known that efficient exciton dissociation in PbSe nanorod (NR) based solar cells requires heterojunction formation to generate free charges. This has been validated in a solar cell utilizing donor-acceptor (D:A) bulk nano-heterojunctions (BNHJ) formed between PbSe quantum dots (QDs) and NRs, known for high MEG yields. Device characterization confirmed that the engineered Type-II interface effectively suppresses recombination losses while enhancing charge separation, achieving over 100% IQE at photon energy threshold of 2.3 times the bandgap energy and 4.09% PCE. In this work, we systematically investigated the role of quantum confinement on charge transfer processes in PbSe BNHJs, particularly in relation to the MEG mechanism. Three distinct BNHJ systems by blending PbSe NRs with PbSe QDs of varied diameters (2.1 nm, 2.9 nm, and 3.3 nm), creating tunable conduction band energy landscapes were fabricated. The energy transfer dynamics were comprehensively characterized through photoluminescence (PL) measurements, revealing diameter-dependent energy transfer efficiencies between NRs and QDs. Complementary terahertz spectroscopy and transient absorption spectroscopy provided insights into charge carrier dynamics and interfacial electronic processes. Solar cells were fabricated and tested under AM1.5G illumination. Current density-voltage and quantum efficiency analysis demonstrated a clear correlation between QD size and device performance.