Synergistic engineering of hole transport materials in perovskite solar cells
Sally Mabrouk,
Behzad Bahrami,
Hytham Elbohy,
Khan Mamun Reza,
Ashim Gurung,
Mao Liang,
Fan Wu,
Mingtai Wang,
Shangfeng Yang,
Qiquan Qiao
Affiliations
Sally Mabrouk
Center for Advanced Photovoltaics, Department of Electrical Engineering and Computer Science South Dakota State University Brookings South Dakota
Behzad Bahrami
Center for Advanced Photovoltaics, Department of Electrical Engineering and Computer Science South Dakota State University Brookings South Dakota
Hytham Elbohy
Physics Department Damietta University New Damietta City Egypt
Khan Mamun Reza
Center for Advanced Photovoltaics, Department of Electrical Engineering and Computer Science South Dakota State University Brookings South Dakota
Ashim Gurung
Center for Advanced Photovoltaics, Department of Electrical Engineering and Computer Science South Dakota State University Brookings South Dakota
Mao Liang
Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Department of Applied Chemistry Tianjin University of Technology Tianjin China
Fan Wu
Key Lab of Optoelectronic Materials and Devices School of Science, Huzhou University Huzhou China
Mingtai Wang
Institute of Applied Technology Hefei Institutes of Physical Science, Chinese Academy of Sciences Hefei China
Shangfeng Yang
Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China Hefei China
Qiquan Qiao
Center for Advanced Photovoltaics, Department of Electrical Engineering and Computer Science South Dakota State University Brookings South Dakota
Abstract In this work, methylammonium lead triiodide (CH3NH3PbI3) perovskite solar cells with efficiencies higher than 18% were achieved using a new nanocomposite hole transport layer (HTL) by doping poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) with a mixed dopant of polyaniline (PANI) and graphene oxide (GO). A synergistic engineering between GO, PANI, and PEDOT:PSS was accomplished to introduce additional energy levels between perovskite and PEDOT:PSS and increase the conductivity of PEDOT:PSS. Kelvin probe force microscope results confirmed that adding GO to PEDOT:PSS/PANI composite significantly reduced the average surface potential. This increased the open circuit voltage (Voc) to 1.05 V for the GO/PEDOT:PSS/PANI nanocomposite perovskite solar cells from the pristine PEDOT:PSS (Voc = 0.95 V) and PEDOT:PSS/PANI (Voc = 0.99 V). In addition, adding PANI to the HTLs substantially enhanced short circuit current density (Jsc). This was supported by the current sensing‐atomic force microscopy (CS‐AFM) and conductivity measurements. The PANI doped films showed superior electrical conductivity compared with those without PANI as indicated by CS‐AFM results. PANI can fill the gaps between the microflakes of GO and give rise to more compact hole transport material (HTM) layer. This led to a higher Jsc after doping with PANI, which was consistent with the incident photon‐to‐current efficiency and electrochemical impedance spectroscopy results. The results of X‐ray diffraction (XRD) and AFM indicated the GO/PANI doped HTMs significantly improved the crystallinity, topography, and crystal size of the perovskite film grown on their surface. A higher efficiency of 18.12% for p‐i‐n perovskite solar cells has been obtained by adding the mixed dopant of GO, PANI, and PEDOT:PSS, demonstrating better stability than the pristine PEDOT:PSS cell.
