scholarly journals Quantifying Polaron Formation and Charge Carrier Cooling in Lead-Iodide Perovskites

2018 ◽  
Vol 30 (29) ◽  
pp. 1707312 ◽  
Author(s):  
Simon A. Bretschneider ◽  
Ivan Ivanov ◽  
Hai I. Wang ◽  
Kiyoshi Miyata ◽  
Xiaoyang Zhu ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Lead Iodide ◽  
Polaron Formation

scholarly journals Surface electron dynamics in hematite (α-Fe2O3): correlation between ultrafast surface electron trapping and small polaron formation

2017 ◽  
Vol 8 (12) ◽  
pp. 8170-8178 ◽  
Author(s):  
Jakub Husek ◽  
Anthony Cirri ◽  
Somnath Biswas ◽  
L. Robert Baker
Keyword(s):  
Charge Carrier ◽  
Small Polaron ◽  
Functional Materials ◽  
Carrier Dynamics ◽  
Electron Trapping ◽  
Electron Dynamics ◽  
Surface Electron ◽  
X Ray ◽  
Charge Carrier Dynamics ◽  
Polaron Formation

Ultrafast soft X-ray reflection-absorption spectroscopy as a probe for following surface charge carrier dynamics in catalytically-relevant functional materials.

scholarly journals The Effect of Structural Dimensionality on Carrier Mobility in Lead-Halide Perovskites

2019 ◽  
Author(s):  
Noor Titan Putri Hartono ◽  
Shijing Sun ◽  
María Gélvez-Rueda ◽  
Polly Pierone ◽  
Matthew Erodici ◽  
...  
Keyword(s):  
Solar Cells ◽  
Charge Carrier ◽  
Carrier Mobility ◽  
Perovskite Solar Cells ◽  
Charge Carrier Mobility ◽  
Lead Iodide ◽  
Optical Pump ◽  
Structural Dimensionality ◽  
Low Dimensional ◽  
Lower Dimensional

<p>Methylammonium lead iodide (MAPI) is a prototypical photo absorber in perovskite solar cells (PSCs), reaching efficiencies above 20%. However, its hygroscopic nature has prompted the quest to find water-resistant alternatives. Recent studies have suggested that mixing MAPI with lower dimensional, bulky-<i>A</i>-site-cation perovskites helps mitigate this environmental instability. On the other hand, low dimensional perovskites suffer from poor device performance, which has been suggested to be due to limited out-of-plane charge carrier mobility resulting from structural dimensionality and large binding energy of the charge carriers. To understand the effects of dimensionality on performance, we systematically mixed MA-based 3D perovskites with larger <i>A</i>-site cation, dimethylammonium, iso-propylammonium, and t-butylammonium lead iodide perovskites. During the shift from MAPI to lower dimensional (LD) PSCs, the efficiency is significantly reduced by 2 orders of magnitude, with short-circuit currents decreasing from above 20 mA/cm<sup>2</sup> to less than 1 mA/cm<sup>2</sup>. In order to explain these decrease in performance, we studied the charge carrier mobilities of these materials using optical-pump/ terahertz-probe, time-resolved microwave photoconductivity, and photoluminescence measurements. The results show that as we add more of the low dimensional perovskites, the mobility decreases by a factor of 20 when it reaches pure LD perovskites. In addition, the photoluminescence decay fitting is slightly slower for the mixed perovskites, suggesting some improvement in the recombination dynamics. These findings indicate that changes in structural dimensionality by mixing<i> A</i>-site cations play an important role in measured charge carrier mobility, and in the performance of perovskite solar cells.</p>

scholarly journals Strontium Insertion in Methylammonium Lead Iodide: Long Charge Carrier Lifetime and High Fill-Factor Solar Cells

2016 ◽  
Vol 28 (44) ◽  
pp. 9839-9845 ◽  
Author(s):  
Daniel Pérez-del-Rey ◽  
Dávid Forgács ◽  
Eline M. Hutter ◽  
Tom J. Savenije ◽  
Dennis Nordlund ◽  
...  
Keyword(s):  
Solar Cells ◽  
Charge Carrier ◽  
Fill Factor ◽  
Carrier Lifetime ◽  
Lead Iodide ◽  
High Fill Factor ◽  
Methylammonium Lead Iodide ◽  
Charge Carrier Lifetime

scholarly journals Photovoltaic mixed-cation lead mixed-halide perovskites: links between crystallinity, photo-stability and electronic properties

2017 ◽  
Vol 10 (1) ◽  
pp. 361-369 ◽  
Author(s):  
Waqaas Rehman ◽  
David P. McMeekin ◽  
Jay B. Patel ◽  
Rebecca L. Milot ◽  
Michael B. Johnston ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Band Gap ◽  
Electronic Properties ◽  
Photovoltaic Cells ◽  
Lead Iodide ◽  
Tunable Materials ◽  
Mixed Cation ◽  
Halide Perovskites ◽  
Compositional Effects ◽  
Photo Stability

We establish compositional effects on stability, crystallinity, charge-carrier life times and mobilities in mixed-cation lead iodide-bromide perovskites as band gap tunable materials for multi-junction photovoltaic cells.

scholarly journals Charge Carrier Relaxation in Colloidal FAPbI3 Nanostructures Using Global Analysis

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1897
Author(s):  
Carolina Villamil Franco ◽  
Benoît Mahler ◽  
Christian Cornaggia ◽  
Thomas Gustavsson ◽  
Elsa Cassette
Keyword(s):  
Charge Carrier ◽  
Transient Absorption ◽  
Global Analysis ◽  
High Energy ◽  
Analysis Method ◽  
Relaxation Dynamics ◽  
Lead Iodide ◽  
Carrier Relaxation ◽  
Spectral Lineshape ◽  
High Energy Tail

We study the hot charge carrier relaxation process in weakly confined hybrid lead iodide perovskite colloidal nanostructures, FAPbI3 (FA = formaminidium), using femtosecond transient absorption (TA). We compare the conventional analysis method based on the extraction of the carrier temperature (Tc) by fitting the high-energy tail of the band-edge bleach with a global analysis method modeling the continuous evolution of the spectral lineshape in time using a simple sequential kinetic model. This practical approach results in a more accurate way to determine the charge carrier relaxation dynamics. At high excitation fluence (density of charge carriers above 1018 cm−3), the cooling time increases up to almost 1 ps in thick nanoplates (NPs) and cubic nanocrystals (NCs), indicating the hot phonon bottleneck effect. Furthermore, Auger heating resulting from the multi-charge carrier recombination process slows down the relaxation even further to tens and hundreds of picoseconds. These two processes could only be well disentangled by analyzing simultaneously the spectral lineshape and amplitude evolution.

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