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arXiv 2102.08319cond-mat.mtrl-sci
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钙钛矿器件中与离子迁移率无关的大信号开关特性

Ion Mobility Independent Large Signal Switching of Perovskite Devices

Saketh Tirupati, Abhimanyu Singareddy, Dhyana Sivadas, Pradeep R. Nair

AI总结:

本研究通过数值模拟与实验验证,揭示钙钛矿器件大信号开关延迟由电子偶极子及接触层耗尽区崩塌主导,且与离子迁移率无关。

摘要:

众所周知,钙钛矿中可移动离子的存在会影响器件的静电特性,从而导致与迟滞、效率衰减、低频电容、大信号开关等相关的多种异常特征。因此,离子迁移率被认为对相关时间常数/延迟具有关键影响。与这一被广泛接受的观点截然不同,我们在此表明,与大信号开关相关的时间延迟表现出一种由电子偶极子而非离子偶极子决定的普适行为。由于由此产生的接触层耗尽区突然且剧烈的崩塌,开关延迟与离子迁移率无关!此外,我们得到实验结果充分支持的详细数值模拟表明,在离子分布弛豫至其稳态条件之前很久,端电流就已表现出接近稳态的行为。这些结果对于理解和优化包括太阳能电池和LED在内的钙钛矿基电子器件具有有趣的启示意义。

英文摘要:

The presence of mobile ions in perovskites is well known to influence the device electrostatics leading to a wide variety of anomalous characteristics related to hysteresis, efficiency degradation, low frequency capacitance, large signal switching, etc. Accordingly, the ion mobility is understood to a have a critical influence on the associated time constants/delays. Quite contrary to this broadly accepted thought, here we show that the time delays associated with large signal switching show a universal behavior dictated by electronic dipoles, rather than ionic dipoles. Due to the resultant sudden and dramatic collapse of contact layer depletion region, switching delays are independent of ion mobilities! Further, our detailed numerical simulations, well supported by experimental results, indicate that terminal currents show near steady state behavior well ahead of the relaxation of ionic distributions to their steady state conditions. These results have interesting implications towards the understanding and optimization of perovskite based electronic devices, including solar cells and LEDs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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