| Autor: |
Tran, Thanh-Xuan, Jang, Yu Jin, Vu, Van-Tu, Jung, Chan-Woo, Do, Van Dam, Jin, Yeongrok, Lee, Jaekwang, Kim, Hyunjung, Kim, Ji-Hee |
| Zdroj: |
Nano Letters; September 2024, Vol. 24 Issue: 36 p11163-11169, 7p |
| Abstrakt: |
Prolonging hot carrier cooling, a crucial factor in optoelectronic applications, including hot carrier photovoltaics, presents a significant challenge. High-energy band-nesting excitons within parallel bands offer a promising and underexplored avenue for addressing this issue. Here, we exploit an exceptional D exciton cooling prolongation of 2 to 3 orders of magnitude compared to sub-picosecond in typical transition metal dichalcogenides (TMDs) owing to the complex Coulomb environment and the sequential and mismatch-valley relaxation. Simultaneously, the intervalley scattering upconversion of band-edge excitons with the slow D exciton formation in the metastable Γ valley/hill also reduces the cooling rate. We successfully extract D and C excitons as hot carriers through integrating with various thicknesses of TiOx, achieving the highest efficiency of 98% and 85% at a Ti thickness of 2 nm. Our findings highlight the potential of band-nesting excitons for extending hot carrier cooling time, paving the way for advancements in hot carrier-based optoelectronic devices. |
| Databáze: |
Supplemental Index |
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