Efficient and Stable Perovskite Solar Cells via Dual Functionalization of Dopamine Semiquinone Radical with Improved Trap Passivation Capabilities

Abstract

Highly efficient planar heterojunction perovskite solar cells (PVSCs) with dopamine (DA) semiquinone radical modified poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) (DA-PEDOT:PSS) as a hole transporting layer (HTL) were fabricated. A combination of characterization techniques were employed to investigate the effects of DA doping on the electron donating capability of DA-PEDOT:PSS, perovskite film quality and charge recombination kinetics in the solar cells. Our study shows that DA doping endows the DA-PEDOT:PSS-modified PVSCs with a higher radical content and greater perovskite to HTL charge extraction capability. In addition, the DA doping also improves work function of the HTL, increases perovskite film crystallinity, and the amino and hydroxyl groups in DA can interact with the undercoordinated Pb atoms on the perovskite crystal, reducing charge-recombination rate and increasing charge-extraction efficiency. Therefore, the DA-PEDOT:PSS-modified solar cells outperform those based on PEDOT:PSS, increasing open-circuit voltage (V oc ) and power conversion efficiency (PCE) to 1.08 V and 18.5%, respectively. Even more importantly, the efficiency of the unencapsulated DA-PEDOT:PSS-based PVSCs are well retained with only 20% PCE loss after exposure to air for 250 hours. These in-depth insights into structure and performance provide clear and novel guidelines for the design of effective HTLs to facilitate the practical application of inverted planar heterojunction PVSCs.

Efficient Perovskite Solar Cells by Reducing Interface‐Mediated Recombination: a Bulky Amine Approach

“…[ 20,23,56,57 ] Therefore in our case, additional effect like repelling electrons from HTL to suppress minority carrier recombination velocity across interfaces can be supposed to explain the prolonged carrier lifetime after NMAI‐treatment. [ 11,17,58,59 ]…”

Interface Engineering for All‐Inorganic CsPbI2Br Perovskite Solar Cells with Efficiency over 14%

“…Park and co‐workers demonstrated defect‐free CsPbI 2 Br film with high crystallinity by optimizing the annealing temperature, thus resulting in an enhanced V oc of 1.23 V . It was found that nonradiative recombination was largely governed by the mismatched energy levels between the perovskite film and the electron transporting layer (ETL) or hole transporting layer (HTL) . Yang and co‐workers reported that modification of the interface between CsPbI 2 Br film and P3HT HTL enables an impressive V oc up to 1.32 V and PCE of 12.02% .…”

Tailored PEDOT:PSS hole transport layer for higher performance in perovskite solar cells: Enhancement of electrical and optical properties with improved morphology

“…Approaches modifying the PEDOT:PSS layer to achieve higher efficiency in PSCs mostly focused on doping [21][22][23][24] or adding interfacial layer [25][26][27][28][29][30][31][32] . Solvent-only treatments have also been considered as an effective method to modify PEDOT:PSS, which till now has been focused only on single step treatment.…”