scholarly journals Influence of Electrical Traps on the Current Density Degradation of Inverted Perovskite Solar Cells

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1644 ◽  
Author(s):  
Hyunho Lee ◽  
Changhee Lee ◽  
Hyung-Jun Song

Premature aging of perovskite solar cells (PSC) is one of the biggest challenges for its commercialization. Particularly, PSCs exhibit rapid degradation of photovoltaic parameters under ambient air exposure. To estimate the degradation mechanism of PSC under air exposure, we systematically analyzed the relationship between electrical traps of the PSC and its degradation. After 240 h of air exposure to the PSC, its power conversion efficiency degraded to 80% compared to its initial value. The loss mainly originated from reduced current density, which is affected by traps and carrier transport in the disordered semiconducting layer. Capacitance–voltage plots of the PSC showed that the ionic doping from the perovskite layer caused an increased number of trap sites at the buffer layer. Moreover, the extrapolation of temperature dependent open circuit voltage graphs indicated that the trap sites lead to poor carrier transport by increasing recombination losses in the aged device. Therefore, trap sites arose from the result of ion migration and caused an early degradation of PSC under air exposure.

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 461 ◽  
Author(s):  
Masaya Taguchi ◽  
Atsushi Suzuki ◽  
Takeo Oku ◽  
Sakiko Fukunishi ◽  
Satoshi Minami ◽  
...  

Perovskite solar cells, in which decaphenylcyclopentasilane (DPPS) layers were formed on the surface of the perovskite layer, were fabricated, and the influence on photovoltaic characteristics was investigated. The devices were fabricated by a spin-coating technique, and the surface morphology and crystal structures were investigated by scanning electron microscopy and X-ray diffraction. By adding the DPPS, the fill factor and open circuit voltage were increased, and the photoelectric conversion efficiency was improved. A stability test in ambient air was carried out for seven weeks, and the photoelectric conversion efficiencies were remarkably improved for the devices with DPPS.


2021 ◽  
Vol 34 (1) ◽  
pp. 01-08
Author(s):  
B GopalKrishna ◽  
Sanjay Tiwari

Perovskite solar cells are emerging photovoltaic devices with PCE of above 25%. Perovskite are suitable light absorber materials in solar cells with excellent properties like appropriate band gap energy, long carrier lifetime and diffusion length, and high extinction coefficient. Simulation study is an important technique to understand working mechanisms of perovskites solar cells. The study would help develop efficient, stable PSCs experimentally. In this study, modeling of perovskite solar cell was carried out through Setfos software. The optimization of different parameters of layer structure of solar cell would help to achieve maximum light absorption in the perovskite layer of solar cell. Simulation study is based drift-diffusion model to study the different parameters of perovskite solar cell. Hysteresis is one of the factors in the perovskite solar cell which may influence the device performance. The measurement of abnormal hysteresis can be done by current-voltage curve during backward scan during simulation study. In backward scan, the measurement starts from biasing voltage higher than open circuit voltage and sweep to voltage below zero. The numerical simulation used to study the various parameters like open circuit voltage, short circuit current, fill factor, power conversion efficiency and hysteresis. The simulation results would help to understand the photophysics of solar cell physics which would help to fabricate highly efficient and stable perovskite solar cells experimentally.


2017 ◽  
Vol 121 (12) ◽  
pp. 6546-6553 ◽  
Author(s):  
Chang Liu ◽  
Wenhui Ding ◽  
Xianyong Zhou ◽  
Jishu Gao ◽  
Chun Cheng ◽  
...  

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1227 ◽  
Author(s):  
Byung Kim ◽  
Woongsik Jang ◽  
Dong Wang

Nickel oxide (NiOx)–based perovskite solar cells (PSCs) have recently gained considerable interest, and exhibit above 20% photovoltaic efficiency. However, the reported syntheses of NiOx sol-gel used toxic chemicals for the catalysts during synthesis, which resulted in a high-temperature annealing requirement to remove the organic catalysts (ligands). Herein, we report a facile “NiOx sol-gel depending on the chain length of various solvents” method that eschews toxic catalysts, to confirm the effect of different types of organic solvents on NiOx synthesis. The optimized conditions of the method resulted in better morphology and an increase in the crystallinity of the perovskite layer. Furthermore, the use of the optimized organic solvent improved the absorbance of the photoactive layer in the PSC device. To compare the electrical properties, a PSC was prepared with a p-i-n structure, and the optimized divalent alcohol-based NiOx as the hole transport layer. This improved the charge transport compared with that for the typical 1,2-ethanediol (ethylene glycol) used in earlier studies. Finally, the optimized solvent-based NiOx enhanced device performance by increasing the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF), compared with those of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)–based devices.


2019 ◽  
Vol 7 (29) ◽  
pp. 17324-17333 ◽  
Author(s):  
Meiyue Liu ◽  
Ziming Chen ◽  
Yongchao Yang ◽  
Hin-Lap Yip ◽  
Yong Cao

Ag diffused across the PCBM layer increased the trap density and down-shifted the energy level of the perovskite layer. Fortunately, PCBM/ZnO layer efficiently suppressed the Ag diffusion, resulting in a perovskite solar cell with PCE of 18.1%.


2021 ◽  
Vol 112 ◽  
pp. 110753
Author(s):  
Sabastine Chinedu Ezike ◽  
Aderemi Babatunde Alabi ◽  
Amarachukwu Nneka Ossai ◽  
Adebayo Olaniyi Aina

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 358 ◽  
Author(s):  
Pao-Hsun Huang ◽  
Yeong-Her Wang ◽  
Chien-Wu Huang ◽  
Wen-Ray Chen ◽  
Chien-Jung Huang

In this paper, we demonstrate that the inverted CH3NH3PbI3 (perovskite) solar cells (PSCs) based on fullerene (C60) as an acceptor is fabricated by applying an improved poly(3,4-ethlyenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution as a hole transport layer (HTL). The power conversion efficiency (PCE) of inverted PSCs is increased by 37.5% with stable values of open-circuit voltage (VOC) and fill factor (FF) because we enhance the viscosity of the PEDOT:PSS solution, indicating the perfect effect on both external quantum efficiency (EQE) and surface grain size. The characteristics of the PEDOT:PSS solution, which is being improved through facile methods of obtaining excellent growth of PEDOT:PSS thin film, have a considerable impact on carrier transport. A series of further processing fabrications, including reliable and feasible heating and stirring techniques before the formation of the PEDOT:PSS thin film via spin-coating, not only evaporate the excess moisture but also obviously increase the conductivity. The raised collection of holes become the reason for the enhanced PCE of 3.0%—therefore, the stable performance of FF and VOC are attributed to lower series resistance of devices and the high-quality film crystallization of perovskite and organic acceptors, respectively.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Takeo Oku ◽  
Junya Nomura ◽  
Atsushi Suzuki ◽  
Hiroki Tanaka ◽  
Sakiko Fukunishi ◽  
...  

Effects of polysilane additions on CH3NH3PbI3 perovskite solar cells were investigated. Photovoltaic cells were fabricated by a spin-coating method using perovskite precursor solutions with polymethyl phenylsilane, polyphenylsilane, or decaphenyl cyclopentasilane (DPPS), and the microstructures were examined by X-ray diffraction and optical microscopy. Open-circuit voltages were increased by introducing these polysilanes, and short-circuit current density was increased by the DPPS addition, which resulted in the improvement of the photoconversion efficiencies to 10.46%. The incident photon-to-current conversion efficiencies were also increased in the range of 400~750 nm. Microstructure analysis indicated the formation of a dense interfacial structure by grain growth and increase of surface coverage of the perovskite layer with DPPS, and the formation of PbI2 was suppressed, leading to the improvement of photovoltaic properties.


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