Details

Autor(en) / Beteiligte

• Yang, Jianfeng
• Wen, Xiaoming
• Xia, Hongze
• Sheng, Rui
• Ma, Qingshan
• Kim, Jincheol
• Tapping, Patrick
• Harada, Takaaki
• Kee, Tak W
• Huang, Fuzhi
• Cheng, Yi-Bing
• Green, Martin
• Ho-Baillie, Anita
• Huang, Shujuan
• Shrestha, Santosh
• Patterson, Robert
• Conibeer, Gavin

Titel

Acoustic-optical phonon up-conversion and hot-phonon bottleneck in lead-halide perovskites

Ist Teil von

• Nature communications, 2017-01, Vol.8 (1), p.14120-14120, Article 14120

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2017

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• The hot-phonon bottleneck effect in lead-halide perovskites (APbX ) prolongs the cooling period of hot charge carriers, an effect that could be used in the next-generation photovoltaics devices. Using ultrafast optical characterization and first-principle calculations, four kinds of lead-halide perovskites (A=FA /MA /Cs , X=I /Br ) are compared in this study to reveal the carrier-phonon dynamics within. Here we show a stronger phonon bottleneck effect in hybrid perovskites than in their inorganic counterparts. Compared with the caesium-based system, a 10 times slower carrier-phonon relaxation rate is observed in FAPbI . The up-conversion of low-energy phonons is proposed to be responsible for the bottleneck effect. The presence of organic cations introduces overlapping phonon branches and facilitates the up-transition of low-energy modes. The blocking of phonon propagation associated with an ultralow thermal conductivity of the material also increases the overall up-conversion efficiency. This result also suggests a new and general method for achieving long-lived hot carriers in materials.