Details

Autor(en) / Beteiligte

• Chen, Chien‐Yu
• Lin, Yung‐I
• Lai, Po‐Ting
• Lin, Hao‐Cheng
• Tan, Guang‐Hsun
• Lin, Hao‐Wu
• Schaller, Richard D.

Titel

Self‐Trapped and Free Exciton Dynamics in Vacuum‐Deposited Cesium Copper Iodide Thin Films

Ist Teil von

• Advanced optical materials, 2022-09, Vol.10 (17), p.n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2022

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Highly photoluminescent, lead‐free perovskites are of interest for displays and solid‐state light‐emitting devices. In this report, streak camera‐based time‐resolved emission and transient absorption spanning visible to deep‐ultraviolet (UV) wavelengths are utilized to study self‐trapped and free exciton dynamics in vacuum‐deposited cesium copper halide thin films of CsCu2I3 and Cs3Cu2I5. Self‐trapped exciton emission of CsCu2I3 exhibits more noticeable changes with time in the peak position and width than Cs3Cu2I5. UV‐to‐blue emission is detectable for both compositions, where free exciton emission is distinct for CsCu2I3. Transient absorption shows loss of ground‐state bleach signals at early time delays for both, and the bleach signal shifts toward higher energy as time delay increases, likely due to strains induced by the newly created self‐trapped excitons. Global analysis performed on the transient absorption results yields time constants in these materials that build an overall dynamic scheme. This work aids in building a complete picture regarding light emission in these promising materials. CsCu2I3 and Cs3Cu2I5 exhibiting self‐trapped exciton emission are attractive for light‐emitting applications. Carrier dynamics of these vapor deposited materials are examined by transient absorption and streak camera measurements. CsCu2I3 exhibits free exciton emission and noticeable changes in width and position of self‐trapped exciton emission in the streak camera results which are not observed in Cs3Cu2I5.