Regensburg 2019 – wissenschaftliches Programm
HL 45.7: Poster
Donnerstag, 4. April 2019, 18:30–21:00, Poster E
π-extended phosphoniumfluorenes: a new type of hole blocking layer in p-i-n perovskite solar cells — •Qingzhi An1,2, Qing Sun1,2, Andreas Weu1,2, Sebastian Amdt3, A.Stephen K Hashmi3,4, and Yana Vaynzof1,2 — 1Kirchhoff-Institut für Physik, Heidelberg, Germany — 2Centre for Advanced Materials,Heidelberg,Germany — 3Organisch-Chemisches Institut,Heidelberg,Germany — 4Chemistry Department,Jeddah,Saudi Arabia
Hole blocking layer (HBL) is applied to p-i-n perovskite solar cells for avoiding charges recombination by blocking the holes transfer to the anode, leading to achieve a higher fill factor (FF) and power conversion efficiency (PCE). In this work, 7 different π-extended phosphoniumfluorene molecules were synthesized and applied as HBL to p-i-n planar heterojunction perovskite solar cells. A combination of characterization techniques was utilized to investigate HBL molecular crystallization and charge recombination kinetics in the solar cells. Our study shows that the HBL can also modify the open circuit voltage (Voc). A better coverage and faster extraction HBL leads to an increase of Voc and PCE to 1.05V and 18%, respectively. Though the in-depth mechanism between Voc and HBL is unclear so far, this work provides new guidelines for designing efficient HBL materials and demonstrates that open circuit voltage can be further improved by HBL.