Transient photovoltage overshoot in multi-cation perovskite solar cells: An interplay between interfacial ionic layer and photoinduced electric field

2021 ◽  
Vol 230 ◽  
pp. 111276
Author(s):  
Vidya Raj ◽  
Sudeshna Ghosh ◽  
Shaibal K. Sarkar
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Perovskite Solar Cells ◽  
Transient Photovoltage ◽  
Ionic Layer

scholarly journals Improving Electron Extraction Ability and Device Stability of Perovskite Solar Cells Using a Compatible PCBM/AZO Electron Transporting Bilayer

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 720 ◽  
Author(s):  
Hang Dong ◽  
Shangzheng Pang ◽  
Yi Zhang ◽  
Dazheng Chen ◽  
Weidong Zhu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Metal Electrode ◽  
Extraction Ability ◽  
Time Resolved ◽  
Recombination Lifetime ◽  
Transient Photovoltage ◽  
Device Stability ◽  
Hole Transporting ◽  
Electron Extraction

Due to the low temperature fabrication process and reduced hysteresis effect, inverted p-i-n structured perovskite solar cells (PSCs) with the PEDOT:PSS as the hole transporting layer and PCBM as the electron transporting layer have attracted considerable attention. However, the energy barrier at the interface between the PCBM layer and the metal electrode, which is due to an energy level mismatch, limits the electron extraction ability. In this work, an inorganic aluminum-doped zinc oxide (AZO) interlayer is inserted between the PCBM layer and the metal electrode so that electrons can be collected efficiently by the electrode. It is shown that with the help of the PCBM/AZO bilayer, the power conversion efficiency of PSCs is significantly improved, with negligible hysteresis and improved device stability. The UPS measurement shows that the AZO interlayer can effectively decrease the energy offset between PCBM and the metal electrode. The steady state photoluminescence, time-resolved photoluminescence, transient photocurrent, and transient photovoltage measurements show that the PSCs with the AZO interlayer have a longer radiative carrier recombination lifetime and more efficient charge extraction efficiency. Moreover, the introduction of the AZO interlayer could protect the underlying perovskite, and thus, greatly improve device stability.

High‐Efficiency Perovskite Solar Cells Enabled by Anatase TiO 2 Nanopyramid Arrays with an Oriented Electric Field

2020 ◽  
Vol 132 (29) ◽  
pp. 12067-12074 ◽  
Author(s):  
Yinhua Lv ◽  
Ruihan Yuan ◽  
Bing Cai ◽  
Behzad Bahrami ◽  
Ashraful Haider Chowdhury ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
High Efficiency ◽  
Perovskite Solar Cells

Origin of Degradation in Perovskite Solar Cells by Intensity Modulated Photovoltage Spectroscopy Measurement (IMVS)

2021 ◽  
Vol 1028 ◽  
pp. 133-137
Author(s):  
Adhita Asma Nurunnizar ◽  
Alvin Fariz ◽  
Herman ◽  
Rahmat Hidayat
Keyword(s):  
Solar Cells ◽  
Charge Carrier ◽  
Conversion Efficiency ◽  
Cell Structure ◽  
Perovskite Solar Cells ◽  
Nyquist Plot ◽  
Frequency Range ◽  
Intensity Modulated ◽  
Transient Photovoltage ◽  
Lower Frequency Range

Perovskite solar cells (PSCs) based on lead halide perovskite have attracted much attention owing to the fast development of their power conversion efficiency (PCE) from 3.8% to 25%. Various factors play important roles in affecting the conversion efficiency of PSCs, such as charge carrier generation, transport, recombination, and collection. In addition, the presence of interfacial defects has also a crucial effect in charge carrier transfer and recombination processes. However, the origin and mechanism of interfacial charge recombinations in PSCs are still not comprehensively investigated. For that purpose, we have performed intensity-modulated photovoltage spectroscopy (IMVS) and transient photovoltage (TPV) measurements of PSCs, which were fabricated with FTO/c-TiO2/mp-TiO2/Perovskite/PTAA/Au cell structure. The solar cell (J-V) characteristics of the PSCs on the day-1, day-2, day-3, and day-6 after the cell fabrication, indicating a significant degradation of the cell with time. The Nyquist plots of IMVS measurement on the same day as the J-V measurement seem to be composed of two semicircles at a lower frequency range and a higher frequency range. The semicircle at the lower frequency range enlarged on the day-6 measurement, but the semicircle at higher frequency decreased. The change of this Nyquist plot is in agreement with a significant decrease in the J-V curves. The semicircle at lower frequency may be assigned to the ion diffusion or migration. Therefore, cell degradation may be caused by the liberation of ions (including iodide) from the surface of the perovskite crystal structure. It then increases recombination loss due to back charge transfer from TiO2 to perovskite as indicated by the changing of the semicircle at high frequency into a smaller semicircle. Therefore, the present results reemphasize that the improvement of PSC stability needs the prevention of ions liberations from the surface by introducing passivation substances. In addition, the results also show the practical usefulness of IMVS for inspecting PSC degradation due to such an ion liberation process.

An Investigation into Electric Field-Modulated Photoluminescence of Perovskite solar cells

MRS Advances ◽  
2017 ◽  
Vol 2 (53) ◽  
pp. 3099-3104
Author(s):  
Zhihua Xu
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Perovskite Solar Cells ◽  
Internal Electric Field ◽  
Ion Migration ◽  
Migration Mechanism ◽  
Halide Perovskites ◽  
Mobile Ions ◽  
Voltage Scanning

ABSTRACTElectric field-modulated photoluminescence (PL) of perovskite solar cells is investigated to gain deeper insight about the role of the mobile ions in organometal halide perovskites. The PL intensity of perovskite solar cells show significant dependence on the polarity of the external electric field and the voltage scanning direction. This phenomenon is discussed in the framework of an ion migration mechanism, which has been widely accounted for the current density-voltage (J-V) hysteresis in perovskite solar cells. The result suggests that the mobile ions not only change the internal electric field of perovskite solar cells, but also have an effect on the recombination of photogenerated charge carriers.

Electric-Field-Induced Degradation of Methylammonium Lead Iodide Perovskite Solar Cells

2016 ◽  
Vol 7 (16) ◽  
pp. 3091-3096 ◽  
Author(s):  
Soohyun Bae ◽  
Seongtak Kim ◽  
Sang-Won Lee ◽  
Kyung Jin Cho ◽  
Sungeun Park ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Perovskite Solar Cells ◽  
Lead Iodide ◽  
Methylammonium Lead Iodide

Interfacial recombination kinetics in aged perovskite solar cells measured using transient photovoltage techniques

Nanoscale ◽  
2019 ◽  
Vol 11 (42) ◽  
pp. 20024-20029 ◽  
Author(s):  
Jesús Jiménez-López ◽  
Emilio Palomares
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Charge Recombination ◽  
Transient Photovoltage ◽  
Interfacial Recombination ◽  
Recombination Kinetics ◽  
Interfacial Charge

The reduction of interfacial charge recombination kinetics in perovskite solar cells is key to increase device photovoltaic efficiencies.

scholarly journals Formation of a Fast Charge Transfer Channel in Quasi-2D Perovskite Solar Cells through External Electric Field Modulation

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7402
Author(s):  
Xixiang Zhu ◽  
Liping Peng ◽  
Jinpeng Li ◽  
Haomiao Yu ◽  
Yulin Xie
Keyword(s):  
Solar Cells ◽  
Charge Transfer ◽  
Electric Field ◽  
Quantum Wells ◽  
External Electric Field ◽  
Perovskite Solar Cells ◽  
Fast Charge ◽  
Transfer Channel ◽  
Local Polarization ◽  
Field Modulation

Quasi-2D perovskites solar cells exhibit excellent environmental stability, but relatively low photovoltaic properties, compared with 3D perovskites solar cells. However, charge transport and extraction in quasi-2D perovskite solar cells are still limited by the inevitable quantum well effect, resulting in low power conversion efficiency (PCE). To date, most efforts concentrate on crystal orientation and favorable alignment during materials and films processing. In this paper, we demonstrated that the quasi-2D perovskite [(BA)2(MA)3Pb4I13 (n = 4)] solar cells show an optimized device performance through forming a fast charge transfer channel among 2D quantum wells through external electric field modulation, with appropriate modulation bias and time after the device has been fabricated. Essentially, ions will move directionally due to local polarization in quasi-2D perovskite solar cells under the action of electric field modulation. More importantly, the mobile ions function as a dopant to de-passivate the defects when releasing at grain boundaries, while decreasing built-in potential by applying forward modulation bias with proper modulation time. The capacitance-voltage characteristics indicate that electric field modulation can decrease the charge accumulation and improve the charge collection in quasi-2D perovskite solar cells. Photoluminescence (PL) studies confirm that the non-radiative recombination is reduced by electric field modulation, leading to enhanced charge transfer. Our work indicates that external electric field modulation is an effective method to form a fast charge transfer channel among 2D quantum wells, leading to enhanced charge transfer and charge collection through local polarization toward developing high–performance quasi-2D perovskite devices.

scholarly journals Evaluation of Active Layer Thickness Influence in Long-Term Stability and Degradation Mechanisms in CsFAPbIBr Perovskite Solar Cells

2021 ◽  
Vol 11 (24) ◽  
pp. 11668
Author(s):  
Mari Carmen López-González ◽  
Gonzalo del Pozo ◽  
Diego Martín-Martín ◽  
Laura Muñoz-Díaz ◽  
José Carlos Pérez-Martínez ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electric Field ◽  
Layer Thickness ◽  
Active Layer ◽  
Perovskite Solar Cells ◽  
Low Frequency ◽  
Strong Increase ◽  
Active Layer Thickness ◽  
Internal Electric Field ◽  
Ion Density

Perovskite solar cells (PSCs) have become very popular due to the high efficiencies achieved. Nevertheless, one of the main challenges for their commercialization is to solve their instability issues. A thorough understanding of the processes taking place in the device is key for the development of this technology. Herein, J-V measurements have been performed to characterize PSCs with different active layer thicknesses. The solar cells’ parameters in pristine devices show no significant dependence on the active layer thickness. However, the evolution of the solar cells’ efficiency under ISOS-L1 protocol reveals a dramatic burn-in degradation, more pronounced for thicker devices. Samples were also characterized using impedance spectroscopy (IS) at different degradation stages, and data were fitted to a three RC/RCPE circuit. The low frequency capacitance in the thickest samples suffers a strong increase with time, which suggests a significant growth in the mobile ion population. This increase in the ion density partially screens the electric field, which yields a reduction in the extracted current and, consequently, the efficiency. This paper has been validated with two-dimensional numerical simulations that corroborate (i) the decrease in the internal electric field in dark conditions in 650 nm devices, and (ii) the consequent reduction in the carrier drift and, therefore, of the effective current extraction and efficiency.

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