具有接近15%能量转换效率的有机太阳能电池

Organic Solar Cells with an Efficiency Approaching 15%

对叠层有机太阳能电池中的前、后子电池之间的光谱匹配性进行了优化调制.最终,选用带隙为1.24 eV的PTB7-Th:IEICO-4F作为后电池,带隙为1.59 eV的J52-2F:IT-M作为前电池制备了叠层电池.在这个叠层有机太阳能电池中,这2个子电池不仅具有互补的吸收光谱,还具有高的外量子效率,实现了对300~1000 nm范围内太阳发射光谱的高效利用.此外,前、后电池的能量损失均得到有效的控制,分别为0.64和0.53 eV.因此,从光伏性能具体参数上来看,本文制备的叠层器件兼具了高短路电流密度(JSC)和高开路电压(VOC)的优势,分别达到13.3 mA/cm^2和1.65 V.该电池在本实验室内部测试的光伏效率高达14.9%,封装之后效率略有降低,由中国计量科学研究院(NIM)验证的光伏效率达到14.0%.这是目前有机光伏领域的国际最高结果.

In this work,we focus on the fine-tuning of absorption spectra to achieve well-matched light response and reducing the energy loss（Eloss = Egopt – e＊VOC,where Egopt is the optical bandgap,and VOC is the open circuit voltage） for the sub-cells of tandem organic solar cells（OSCs） to improve photovoltaic performance.We select PTB7-Th：IEICO-4F with a band gap of 1.24 eV as the rear cell and J52-2F：IT-M with a band gap of 1.59 eV as the front cell to fabricate the tandem OSCs.The absorption spectra of PTB7-Th：IEICO-4F is mainly located in the region of 600-950 nm,while that of J52-2F：IT-M is mainly located in the region of 450-750 nm.Their response spectra are very complementary,and both of the sub-cells show high external quantum efficiency,prompting the tandem OSCs to realize high-efficiency utilization of solar spectrum in the range of 300-1000 nm.In this tandem OSC,the Eloss in both front and rear cells are also effectively controlled to be 0.64 and 0.53 eV,respectively.In addition,an efficient interconnection layer（ICL） of Zn O/PCP-Na is used to connect the front and the rear sub-cells,which shows outstanding diode characteristics and high light transmittance in the long wavelength direction.In view of these excellent properties,the tandem solar cells manufactured in this work possess the advantages of high short-circuit current density（JSC） and VOC,reaching 13.3 m A/cm^2 and 1.65 V,respectively.The highest power conversion efficiency（PCE） of the tandem OSC reaches 14.9%.The device parameters decrease slightly after encapsulation due to the intense ultraviolet irradiation,and a certified PCE of 14.0%,with a VOC of 1.64 V,a JSC of 12.9 mA/cm^2,and a fill factor（FF） of 0.664,recorded by National Institute of Metrology（NIM）,China.This result is the best obtained in the organic photovoltaic field.