Suppressing Leakage Currents and Improving Performance of Indoor Organic Photovoltaic Devices

降低漏电流并提升室内有机光伏器件光伏性能

Organic photovoltaic(OPV) devices hold great promise for indoor light harvesting,offering a theoretical upper limit of power conversion efficiency that surpasses that of other photovoltaic technologies.However,the presence of high leakage currents in OPV devices commonly constrains their effective performance under indoor conditions.In this study,we identified that the origin of the high leakage currents in OPV devices lay in pinhole defects present within the active layer(AL).By integrating an automated spin-coating strategy with sequential deposition processes,we achieved the compactness of the AL and minimized the occurrence of pinhole defects therein.Experimental findings demonstrated that with an increase in the number of deposition cycles,the density of pinhole defects in the AL underwent a marked reduction.Consequently,the leakage current experienced a substantial decrease by several orders of magnitude which achieved through well-calibrated AL deposition procedures.This enabled a twofold enhancement in the power conversion efficiency(PCE) of the OPV devices under conditions of indoor illumination.

有机光伏(organic photovoltaic,OPV)器件在室内光采集方面前景广阔,其功率转换效率的理论上限超过了其他光伏技术。然而,OPV器件中高漏电流的存在通常会限制其在室内条件下的有效性能。该研究证实了OPV器件中高漏电流的起源在于薄膜层内存在的针孔缺陷。将自动旋涂策略与顺序沉积工艺相结合,显著提高了活性层的紧凑性,并将针孔缺陷的发生降至最低。试验结果表明,随着沉积循环次数的增加,活性层中针孔缺陷的密度显著降低,因而漏电流显著降低了几个数量级。这是通过不断优化活化层沉积工艺而实现的。这使OPV器件在室内照明条件下的功率转换效率提高了两倍。