The recent emerging progress of quantum dot ink(QD-ink)has overcome the complexity of multiple-step colloidal QD(CQD)film preparation and pronouncedly promoted the device performance.However,the detrimental hydroxyl(O...The recent emerging progress of quantum dot ink(QD-ink)has overcome the complexity of multiple-step colloidal QD(CQD)film preparation and pronouncedly promoted the device performance.However,the detrimental hydroxyl(OH)ligands induced from synthesis procedure have not been completely removed.Here,a halide ligand additive strategy was devised to optimize QD-ink process.It simultaneously reduced sub-bandgap states and converted them into iodide-passivated surface,which increase carrier mobility of the QDs films and achieve thicker absorber with improved performances.The corresponding power conversion efficiency of this optimized device reached 10.78%.(The control device was 9.56%.)Therefore,this stratege can support as a candidate strategy to solve the QD original limitation caused by hydroxyl ligands,which is also compatible with other CQD-based optoelectronic devices.展开更多
Comparing with hot researches in absorber layer,window layer has attracted less attention in PbS quantum dot solar cells(QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and...Comparing with hot researches in absorber layer,window layer has attracted less attention in PbS quantum dot solar cells(QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and so on.Herein, ZnO window layer was systematically investigated for its roles in QD SCs performance. The physical mechanism of improved performance was also explored. It was found that the optimized ZnO films with appropriate thickness and doping concentration can balance the optical and electrical properties, and its energy band align well with the absorber layer for efficient charge extraction. Further characterizations demonstrated that the window layer optimization can help to reduce the surface defects, improve the heterojunction quality, as well as extend the depletion width. Compared with the control devices, the optimized devices have obtained an efficiency of 6.7% with an enhanced V_(oc) of 18%, J_(sc) of 21%, FF of 10%, and power conversion efficiency of 58%. The present work suggests a useful strategy to improve the device performance by optimizing the window layer besides the absorber layer.展开更多
基金financially supported by National Natural Science Foundation of China (61874165,51761145048,and 21833009)the Foundation of Shenzhen Science and Technology Innovation Committee (JCYJ20170413113645633)+2 种基金Major State Basic Research Development Program of China (2016YFB0700702)the Guangdong-Hong Kong joint innovation project (2016A050503012)Guangdong Natural Science Funds for Distinguished Young Scholars (2015A030306044)
文摘The recent emerging progress of quantum dot ink(QD-ink)has overcome the complexity of multiple-step colloidal QD(CQD)film preparation and pronouncedly promoted the device performance.However,the detrimental hydroxyl(OH)ligands induced from synthesis procedure have not been completely removed.Here,a halide ligand additive strategy was devised to optimize QD-ink process.It simultaneously reduced sub-bandgap states and converted them into iodide-passivated surface,which increase carrier mobility of the QDs films and achieve thicker absorber with improved performances.The corresponding power conversion efficiency of this optimized device reached 10.78%.(The control device was 9.56%.)Therefore,this stratege can support as a candidate strategy to solve the QD original limitation caused by hydroxyl ligands,which is also compatible with other CQD-based optoelectronic devices.
基金financially supported by the National Natural Science Foundation of China(61306137,51602114)the Research Fund for the Doctoral Program of Higher Education(20130142120075)+2 种基金the Fundamental Research Funds for the Central Universities(HUST:2016YXMS032)the Guangdong-Hong Kong joint innovation project(Grant No.2016A050503012)the Guangdong Natural Science Funds for Distinguished Young Scholars(Grant No.2015A030306044)
文摘Comparing with hot researches in absorber layer,window layer has attracted less attention in PbS quantum dot solar cells(QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and so on.Herein, ZnO window layer was systematically investigated for its roles in QD SCs performance. The physical mechanism of improved performance was also explored. It was found that the optimized ZnO films with appropriate thickness and doping concentration can balance the optical and electrical properties, and its energy band align well with the absorber layer for efficient charge extraction. Further characterizations demonstrated that the window layer optimization can help to reduce the surface defects, improve the heterojunction quality, as well as extend the depletion width. Compared with the control devices, the optimized devices have obtained an efficiency of 6.7% with an enhanced V_(oc) of 18%, J_(sc) of 21%, FF of 10%, and power conversion efficiency of 58%. The present work suggests a useful strategy to improve the device performance by optimizing the window layer besides the absorber layer.
