Reduced voltage losses yield 10% efficient fullerene free organic solar cells with >1 V open circuit voltages.
Reduced voltage losses yield 10% efficient fullerene free organic solar cells with >1 V open circuit voltages.
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DOI：
10.1039/c6ee02598f
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发表时间：
2016-12-01
影响因子：
32.5
通讯作者：
McCulloch I
中科院分区：
文献类型：
--
作者：
Baran D;Kirchartz T;Wheeler S;Dimitrov S;Abdelsamie M;Gorman J;Ashraf RS;Holliday S;Wadsworth A;Gasparini N;Kaienburg P;Yan H;Amassian A;Brabec CJ;Durrant JR;McCulloch I
具有优化能级的非富勒烯受体能够使10%效率的太阳能电池具有降低的电压损失<0.6 V。有机太阳能电池的供体-受体界面处的能级的优化已经将其效率驱动到10%以上。然而，由于高复合损耗，进一步提高与无机太阳能电池相当的效率仍然具有挑战性，这根据经验将开路电压（V oc）限制为通常小于1 V。在这里，我们表明，使用与低带隙聚合物PffBT 4 T-2DT混合的非富勒烯受体可以克服这种经验限制，从而使效率接近10%（9.95%）。我们实现了高达1.12 V的Voc，这对应于聚合物的光学带隙Eg和Voc之间仅Eg/q-Voc = 0.5 ± 0.01 V的损耗。这种高V oc被证明是与实现显着低的非成对和非辐射复合损失在这些设备。非辐射复合的抑制意味着高的外部电致发光量子效率，其数量级高于采用富勒烯受体的等效器件。使用减少复合损失和良好的光电流产生效率之间的平衡实验作为基线的有机太阳能电池的效率潜力的模拟，我们估计，高达20%的效率是可以实现的，如果带隙和填充因子进一步优化。
Non-fullerene acceptors with optimized energy levels enable 10% efficient solar cells with reduced voltage losses <0.6 V. Optimization of the energy levels at the donor–acceptor interface of organic solar cells has driven their efficiencies to above 10%. However, further improvements towards efficiencies comparable with inorganic solar cells remain challenging because of high recombination losses, which empirically limit the open-circuit voltage (V oc) to typically less than 1 V. Here we show that this empirical limit can be overcome using non-fullerene acceptors blended with the low band gap polymer PffBT4T-2DT leading to efficiencies approaching 10% (9.95%). We achieve V oc up to 1.12 V, which corresponds to a loss of only E g/q – V oc = 0.5 ± 0.01 V between the optical bandgap E g of the polymer and V oc. This high V oc is shown to be associated with the achievement of remarkably low non-geminate and non-radiative recombination losses in these devices. Suppression of non-radiative recombination implies high external electroluminescence quantum efficiencies which are orders of magnitude higher than those of equivalent devices employing fullerene acceptors. Using the balance between reduced recombination losses and good photocurrent generation efficiencies achieved experimentally as a baseline for simulations of the efficiency potential of organic solar cells, we estimate that efficiencies of up to 20% are achievable if band gaps and fill factors are further optimized.
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影响因子：
16.6
作者：
Bartesaghi, Davide;Perez, Irene del Carmen;Kniepert, Juliane;Roland, Steffen;Turbiez, Mathieu;Neher, Dieter;Koster, L. Jan Anton
通讯作者：
Koster, L. Jan Anton
影响因子：
27.8
作者：
Hawks, Steven A.;Deledalle, Florent;Durrant, James R.
通讯作者：
Durrant, James R.
影响因子：
27.8
作者：
Faist, Mark A.;Shoaee, Safa;Nelson, Jenny
通讯作者：
Nelson, Jenny
影响因子：
5
作者：
Dimitrov, Stoichko D.;Schroeder, Bob C.;Durrant, James R.
通讯作者：
Durrant, James R.
影响因子：
3.7
作者：
Baran, Derya;Vezie, Michelle S.;Brabec, Christoph J.
通讯作者：
Brabec, Christoph J.