Thermal artefacts in two-photon solar cell experiments
Thermal artefacts in two-photon solar cell experiments
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双光子太阳能电池实验中的热伪影
DOI：
10.1038/s41467-018-07166-1
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发表时间：
2019
影响因子：
16.6
通讯作者：
C. Phillips
中科院分区：
文献类型：
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作者：
C. Phillips
Asahi等人最近报道了异质结太阳能电池在用低于带隙能量的光照射时的外量子效率（EQE）的1个记录增加（ΔEQE）。EQE是在零偏压下光电流电子通量与入射光子通量的比率。这种“两步光子上转换”效应提供了一种突破31%理论肖克利-奎塞尔太阳能电池效率极限的方法。然而，器件传输对温度非常敏感，10 K的温度升高（见图3b，参考文献1）会使光电流本身增加约30%。带隙以下的光是连续波（CW）和强烈的（约360 mWcm − 2）。带隙光（波长λ =~ 780 nm）在GaAs中产生光生载流子对，它们被耗尽场分开。据称，在220 meV的高Al 0下，光电子积累在长寿命的中间态3中。3GA0. 7As/GaAs异质结势垒在耗尽区，然后被带隙以下（λ= 1300 nm）的光激发，从而提高效率。
Asahi et al. recently reported 1 record increases (ΔEQE) in the external quantum efficiency (EQE) of a heterojunction solar cell when it is illuminated with below-bandgap energy light. The EQE is the ratio of photocurrent electron flux to incident photon flux at zero bias. This ‘two-step photon up-conversion’effect offers a way of breaking the 31% theoretical Shockley–Queisser solar cell efficiency limit 2. However, the device transport is very temperature sensitive, and a 10 K temperature rise (see Fig. 3b, ref. 1) increases the photocurrent by about 30% on its own 1. The below-bandgap light is continuous wave (CW) and intense (about 360mWcm− 2). Here it is argued that the observed photocurrent increase is due to sample heating, not direct photoexcitation.Bandgap light (wavelength, λ of∼ 780 nm) creates photocarrier pairs in the GaAs which are separated by the depletion field. It is claimed that photoelectrons accumulate in a long-lived intermediate state 3 at a 220meV high Al0. 3Ga0. 7As/GaAs heterojunction barrier in the depletion zone, before being photoexcited over it by the below bandgap (λ= 1300nm) light and thus increasing the efficiency.
影响因子：
16.6
作者：
Asahi S;Teranishi H;Kusaki K;Kaizu T;Kita T
通讯作者：
Kita T