Chuang Zhao

Bio: Chuang Zhao is an academic researcher from Lanzhou Jiaotong University. The author has contributed to research in topics: HOMO/LUMO & Perovskite (structure). The author has an hindex of 2, co-authored 2 publications receiving 42 citations.

Improving the performance of perovskite solar cells with glycerol-doped PEDOT:PSS buffer layer*

Abstract: In this paper, we investigate the effects of glycerol doping on transmittance, conductivity and surface morphology of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)) (PEDOT:PSS) and its influence on the performance of perovskite solar cells. . The conductivity of PEDOT:PSS is improved obviously by doping glycerol. The maximum of the conductivity is 0.89 S/cm when the doping concentration reaches 6 wt%, which increases about 127 times compared with undoped. The perovskite solar cells are fabricated with a configuration of indium tin oxide (ITO)/PEDOT:PSS/CH3NH3PbI3/PC61BM/Al, where PEDOT:PSS and PC61BM are used as hole and electron transport layers, respectively. The results show an improvement of hole charge transport as well as an increase of short-circuit current density and a reduction of series resistance, owing to the higher conductivity of the doped PEDOT:PSS. Consequently, it improves the whole performance of perovskite solar cell. The power conversion efficiency (PCE) of the device is improved from 8.57% to 11.03% under AM 1.5 G (100 mW/cm2 illumination) after the buffer layer has been modified.

Effect of alkylthiophene spacers and fluorine on the optoelectronic properties of 5,10-bis(dialkylthien-2-yl)dithieno[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene-alt-benzothiadiazole derivative copolymers

Abstract: Alternating conjugated copolymers based on 5,10-bis(dialkylthien-2-yl)dithieno[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene (DTBDT) and 2,1,3-benzothiadiazole (BT) or 5,6-difluoro-2,1,3-benzothiadiazole (FBT) with alkylthiopene spacers were synthesized, and the effect of insertion of alkylthiophene spacers and fluorine atoms on the characteristics of the copolymers, such as the energy levels, intrachain π–π interaction, dielectric constants, photovoltaic properties, etc., were systematically investigated. It has been found that: (i) the introduction of alkylthiophene spacers not only led to an increase in the intrachain interaction of the copolymers, but also resulted in an increase in the highest occupied molecular orbital (HOMO) levels and the lowest unoccupied molecular orbital (LUMO) levels, and (ii) the inclusion of fluorine atoms resulted in a decrease in both HOMO and LUMO energy levels with enhancement of the planarity and hole mobility. However, the inclusion of fluorine atoms had little effect on the LUMO levels relative to the decrease in the HOMO levels, and almost did not affect the dielectric constant of the copolymers. Use of the materials in polymeric photovoltaic cells led to high performance photovoltaic cells (PVCs) with power conversion efficiencies of 6.04–7.12%. The results demonstrated that the optoelectronic and aggregation properties of the 5,10-bis(alkylthien-2-yl)dithieno-[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene-alt-benzothiadiazole derivative copolymers can be effectively regulated by the introduction of alkylthiophene spacers and/or fluorine atoms into the backbone.

Recent Progress of Inverted Perovskite Solar Cells with a Modified PEDOT:PSS Hole Transport Layer.

Abstract: Organic–inorganic hybrid perovskite solar cells (PSCs) has achieved the power conversion efficiency (PCE) of 25.2% in the last 10 years, and the PCE of inverted PSCs has reached >22%. The rapid enh...

Solution-Processed Lithium-Doped ZnO Electron Transport Layer for Efficient Triple Cation (Rb, MA, FA) Perovskite Solar Cells

Abstract: The current work reports the lithium (Li) doping of a low-temperature processed zinc oxide (ZnO) electron transport layer (ETL) for highly efficient, triple-cation-based MA0.57FA0.38Rb0.05PbI3 (MA: methylammonium, FA: formamidinium, Rb: rubidium) perovskite solar cells (PSCs). Lithium intercalation in the host ZnO lattice structure is dominated by interstitial doping phenomena, which passivates the intrinsic defects in ZnO film. In addition, interstitial Li doping also downshifts the Fermi energy position of Li-doped ETL by 30 meV, which contributes to the reduction of the electron injection barrier from the photoactive perovskite layer. Compared to the pristine ZnO, the power conversion efficiency (PCE) of the PSCs incorporating lithium-doped ZnO (Li-doped) is raised from 14.07 to 16.14%. The superior performance is attributed to the reduced current leakage, enhanced charge extraction characteristics, and mitigated trap-assisted recombination phenomena in Li-doped devices, thoroughly investigated by mean...