TY  - JOUR
A1  - Le Corre, Vincent M.
A1  - Diekmann, Jonas
A1  - Peña-Camargo, Francisco
A1  - Thiesbrummel, Jarla
A1  - Tokmoldin, Nurlan
A1  - Gutierrez-Partida, Emilio
A1  - Peters, Karol Pawel
A1  - Perdigón-Toro, Lorena
A1  - Futscher, Moritz H.
A1  - Lang, Felix
A1  - Warby, Jonathan
A1  - Snaith, Henry J.
A1  - Neher, Dieter
A1  - Stolterfoht, Martin
T1  - Quantification of efficiency losses due to mobile ions in Perovskite solar cells via fast hysteresis measurements
JF  - Solar RRL
N2  - Perovskite semiconductors differ from most inorganic and organic semiconductors due to the presence of mobile ions in the material. Although the phenomenon is intensively investigated, important questions such as the exact impact of the mobile ions on the steady-state power conversion efficiency (PCE) and stability remain. Herein, a simple method is proposed to estimate the efficiency loss due to mobile ions via "fast-hysteresis" measurements by preventing the perturbation of mobile ions out of their equilibrium position at fast scan speeds (approximate to 1000 V s(-1)). The "ion-free" PCE is between 1% and 3% higher than the steady-state PCE, demonstrating the importance of ion-induced losses, even in cells with low levels of hysteresis at typical scan speeds (approximate to 100mv s(-1)). The hysteresis over many orders of magnitude in scan speed provides important information on the effective ion diffusion constant from the peak hysteresis position. The fast-hysteresis measurements are corroborated by transient charge extraction and capacitance measurements and numerical simulations, which confirm the experimental findings and provide important insights into the charge carrier dynamics. The proposed method to quantify PCE losses due to field screening induced by mobile ions clarifies several important experimental observations and opens up a large range of future experiments.
KW  - hysteresis
KW  - mobile ions
KW  - perovskite solar cells
Y1  - 2021
U6  - https://doi.org/10.1002/solr.202100772
SN  - 2367-198X
VL  - 6
IS  - 4
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Omarova, Zhansaya
A1  - Yerezhep, Darkhan
A1  - Aldiyarov, Abdurakhman
A1  - Tokmoldin, Nurlan
T1  - In Silico Investigation of the Impact of Hole-Transport Layers on the Performance of CH3NH3SnI3 Perovskite Photovoltaic Cells
JF  - Crystals
N2  - Perovskite solar cells represent one of the recent success stories in photovoltaics. The device efficiency has been steadily increasing over the past years, but further work is needed to enhance the performance, for example, through the reduction of defects to prevent carrier recombination. SCAPS-1D simulations were performed to assess efficiency limits and identify approaches to decrease the impact of defects, through the selection of an optimal hole-transport material and a hole-collecting electrode. Particular attention was given to evaluation of the influence of bulk defects within light-absorbing CH3NH3SnI3 layers. In addition, the study demonstrates the influence of interface defects at the TiO2/CH3NH3SnI3 (IL1) and CH3NH3SnI3/HTL (IL2) interfaces across the similar range of defect densities. Finally, the optimal device architecture TiO2/CH3NH3SnI3/Cu2O is proposed for the given absorber layer using the readily available Cu2O hole-transporting material with PCE = 27.95%, FF = 84.05%, V-OC = 1.02 V and J(SC) = 32.60 mA/cm(2), providing optimal performance and enhanced resistance to defects.
KW  - perovskite solar cells
KW  - CH3NH3SnI3
KW  - SCAPS-1D
KW  - modeling
KW  - HTL
Y1  - 2022
U6  - https://doi.org/10.3390/cryst12050699
SN  - 2073-4352
VL  - 12
IS  - 5
PB  - MDPI
CY  - Basel
ER  -