The viability of double perovskite Cs₂AgBiBr₆ in low-light environments is studied for CO₂ photoreduction. It is observed that light intensity significantly influences product formation with I^0.56 depending on the overall product formation rate. The photodetection measurement reveals that photocurrent as a function of incident power follows a power law ∝ I₀^α with α  = 0.80, which is attributed to the carrier trapping at higher light power. Furthermore, power-dependent transient absorption spectroscopy is studied and observed that at higher fluence, carrier scattering can be dominating. Interestingly, it is found that at higher power, hot carrier relaxation dynamics are altered, and electron-phonon coupling is enhanced, resulting in a lower carrier concentration participating in the photocatalytic reaction, which can limit charge carrier extraction and CO₂ reduction. This study highlights the potential of perovskite semiconductors as promising candidates for photocatalytic reactions in low-light conditions, broadening their applicability in real-world scenarios.

中文翻译：

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揭示卤化物钙钛矿在弱光条件下季节性自适应二氧化碳光还原的潜力

_{研究了双钙钛矿 Cs 2} AgBiBr ₆在弱光环境中用于 CO ₂光还原的可行性。据观察，光强度显着影响产物形成，I 为^0.56，具体取决于总体产物形成速率。光电检测测量表明，光电流作为入射功率的函数遵循幂律∝  I ₀ ^α，其中α  = 0.80，这归因于较高光功率下的载流子捕获。此外，研究并观察到与功率相关的瞬态吸收光谱在较高能量密度下，载流子散射可能占主导地位。有趣的是，我们发现在较高功率下，热载流子弛豫动力学发生改变，电子-声子耦合增强，导致参与光催化反应的载流子浓度较低，这可以限制载流子提取和CO ₂还原。这项研究强调了钙钛矿半导体作为低光条件下光催化反应的有希望的候选者的潜力，扩大了它们在现实世界中的适用性。