Aho Timo, Elsehrawy Farid, Tukiainen Antti, Ranta Sanna, Raappana Marianna, Isoaho Riku, Aho Arto, Hietalahti Arttu, Cappelluti Federica, Guina Mircea
Appl Opt. 2020 Jul 20;59(21):6304-6308. doi: 10.1364/AO.396590.
Quantum dot solar cells are promising for next-generation photovoltaics owing to their potential for improved device efficiency related to bandgap tailoring and quantum confinement of charge carriers. Yet implementing effective photon management to increase the absorptivity of the quantum dots is instrumental. To this end, the performance of thin-film InAs/GaAs quantum dot solar cells with planar and structured back reflectors is reported. The experimental thin-film solar cells with planar reflectors exhibited a bandgap-voltage offset of 0.3 V with an open circuit voltage of 0.884 V, which is one of the highest values reported for quantum dot solar cells grown by molecular beam epitaxy to our knowledge. Using measured external quantum efficiency and current-voltage characteristics, we parametrize a simulation model that was used to design an advanced reflector with diffractive pyramidal gratings revealing a 12-fold increase of the photocurrent generation in the quantum dot layers.
量子点太阳能电池因其在通过带隙剪裁和电荷载流子的量子限制来提高器件效率方面的潜力，而有望用于下一代光伏技术。然而，实施有效的光子管理以提高量子点的吸收率至关重要。为此，本文报道了具有平面和结构化背反射器的薄膜InAs/GaAs量子点太阳能电池的性能。具有平面反射器的实验性薄膜太阳能电池表现出0.3 V的带隙-电压偏移，开路电压为0.884 V，据我们所知，这是通过分子束外延生长的量子点太阳能电池所报道的最高值之一。利用测量的外部量子效率和电流-电压特性，我们对一个模拟模型进行了参数化，该模型用于设计一种带有衍射金字塔光栅的先进反射器，结果显示量子点层中的光电流产生增加了12倍。
