Electron-hole Recombination Process Research Articles

Bleaching studies on Al-hole ([AlO4/h]0) electron spin resonance (ESR) signal in sedimentary quartz

Electron spin resonance (ESR) dating of sediments using quartz is most commonly used for older sediments (>100 ka), since large residuals render the ESR signal unsuitable for dating young sediments. The multiple-centre approach (utilising both Ti and [AlO4/h]0 signals) is usually used to test the resetting of the signals used for ESR dating. Here we work towards a better understanding of, and correction for, the residual signal in ESR samples of sedimentary quartz. We undertook multiple-centre ESR measurements using quartz [AlO4/h]0 and Ti signals on young aeolian samples of different grain sizes which have been independently dated using optically stimulated luminescence (OSL). Our results demonstrate that [AlO4/h]0 signal yields residuals indicating equivalent doses of about 500 Gy, substantially older than expected for the known OSL equivalent doses in the range of 8–37 Gy. The decay of [AlO4/h]0 signal as function of bleaching time can be represented by an exponential function. We investigate the dependence of the residual magnitude of the ESR signal as a function of the previous given dose and observe an exponential increase in the residual signal with dose. Such observations are consistent with the results of luminescence process modelling conducted for a model comprising two luminescence centres and several traps, one of which is a so-called deep disconnected trap that cannot be emptied during optical stimulation. We propose that bleaching occurs through an electron-hole recombination process with electrons released from optically sensitive traps. In addition to our new insights into the bleaching mechanisms of the [AlO4/h]0 ESR signal, we discuss the implications for the procedures used for performing residual dose corrections in ESR dating. We recommend that modern analogues be used in addition to laboratory-bleached samples when performing residual dose corrections.

A sensitive x-ray storage phosphor based on BaFBr:Eu2+, KF/LiF with higher storage stability

A sensitive x-ray storage phosphor based on fluorine excess BaFBr:Eu2+,KF/LiF possessing high storage stability has been synthesized. The electron-hole recombination process giving rise to photostimulated luminescence (PSL) is described. No red shift in the stimulation spectra on alkali co-doping and thus no electron trapping at the Br− vacancies beside the alkali compounds were observed. The enhanced photoluminescence (PL) and PSL efficiencies could very well be explained by the synergistic flux action of the co-dopant(s) and BaBr2 at 850 °C which increases the crystallinity and doping efficiency. Sintering temperatures >900 °C enhanced the luminescence efficiencies of BaFBr:Eu2+ and BaFBr:Eu2+,KBr due to thermal migration of Fi− ions.

WO3/TiO2 Hybrids and Their Applications for the Photocatalytic Degradation of P-Substituted Phenols

Tungsten trioxide (WO3) has received a great attention in last decade because of its commercial applications in smart windows, display devices, mobile phones, photocatalysis, solar cells and hydrogen generation. Due to a bandgap around 2.8 eV, WO3 is a semiconductor suitable for photocatalytic and photovoltaic applications using sunlight1, in contrast to most popular TiO2 of the bandgap of about 3.2 eV.2 However, a combination of WO3 with TiO2 leads to significantly enhancement of photoactivity of the system mainly due to increased separation efficiency of photogenerated electron-hole pairs3. When these charge carriers reach the semiconductor/solution interface, they may be involved in the surface reactions leading to decomposition of pollutants. These reactions occur via formation of highly reactive intermediates, such as hydroxyl radicals and superoxide radicals that break down organic pollutants into safe, smaller compounds such as carbon dioxide, water, and short-chain acids.5 Photocatalysis is important in the degradation of phenolic compounds, for example 4-chlorophenol that are products of industrial waste.4 This method is both eco-friendly and inexpensive. Tungsten trioxide and its composites were synthesized on indium-doped tin oxide (ITO) plates using sol-gel, electrochemical and hydrothermal methods. The morphology and composition of the synthesized WO3 and WO3/TiO2 hybrid were characterized using SEM, XRD, UV-Vis and an optical microscope. Electrochemical studies including cyclic voltammetry and chronoamperometry were performed to test their photoactivity. Lastly, the samples were used in the photocatalytic degradation of 4-chlorophenol monitored by UV-vis spectroscopy. Chronoamperometry studies showed that the WO3 by itself had a rapid electron-hole recombination rate. After combination with TiO2, the charge recombination rate decreased and the system was rapidly stabilized under illumination. The photoactivity of WO3 and WO3/TiO2 hybrid was measured with the use of cyclic voltammetry. HPLC analysis of the degradation products of 4-chlorophenol over time using the TiO2/WO3 composite indicated that the hybrid was able to degrade the pollutant more effectively, in a shorter time than WO3 alone. The addition of TiO2 to WO3 deposited on ITO resulted in increase of photoactivity of the system due to slowing down the electron-hole recombination process. Secondly, the degradation of 4-chlorophenol was more efficient using the WO3/TiO2 system. Future experiments will be focused on explanation of differences in the degradation mechanisms of 4-chlorophenol with the use of WO3 alone and WO3/TiO2 hybrid. The effect of the ratio of TiO2 and WO3 in the hybrid on photoactivity and photocatalytic degradation will also be explored. Tada et. al, Langmuir. 20, 4665-4670 (2004)Dette et. al, Nano Lett. 14, 6533-6538 (2014)DohLevil-Mitrovil et. al, Materials Research Bulletin. 83, 217-224 (2016)Meng et. al, Materials Science and Engineering: B. 180, 20-26 (2014)Linsebigler et. al, Chem. Rev. 95, 735-758 (1995)

Electron transition and electron-hole recombination processes in epitaxial BaTiO3 films with embedded Co nanocrystals

An epitaxial BaTiO3 (BTO) film with embedded Co nanocrystals (NCs) was prepared according to interfacial engineering. Compared with the polycrystalline matrix in previous NCs-matrix systems, the current single-crystal BTO matrix possessed no grains and grain boundaries. The NCs and interface between the NCs and BTO could be regard as the grains and grain boundaries in the NCs-matrix system, respectively. By modulating the size (D) of Co NCs and spacing (R) between the NCs, we achieved the tuneable band gap, Schottky barrier height, the width of potential barrier and well of the nanocomposites. The electron transition and electron-hole recombination processes was well clarified for the NCs-matrix system. An ideal model was provided for explaining the effects of the interaction for NCs, grains and grain boundaries on the photoelectricity nature of materials.

Real-space exciton distribution in strained-siligraphene g-SiC7

Siligraphene belonging to the family of two-dimensional (2D) materials has great potential in optoelectronics due to its considerable excitonic effects. In this study, the strain effects on the electronic structure and the real-space exciton wave functions of g-SiC7 are investigated using the first-principles calculations based on the ab initio many-body perturbation theory. Alongside the increase (decrease) of the bandgap with compressive (tensile) strain, our results show that the exciton in the siligraphene monolayer under in-plane biaxial compressive strains is much more localized than that in the case of tensile one, leading to the higher and lower exciton binding energies, respectively. Moreover, the π↦π and π↦σ exciton state transition emerges when applying the compressive and tensile strains, respectively. Overall, our study reveals that a desirable way to dissociate the electron-hole coupling and to reduce the electron-hole recombination process is applying “in-plane biaxial tensile strain,” making g-SiC7 an excellent potential functional 2D semiconductor in optoelectronics.

Synthesis of Cu/TiO2 catalysts by reactive magnetron sputtering deposition and its application for photocatalytic reduction of CO2 and H2O to CH4

In the present work, a series of Cu/TiO2 catalysts were successfully synthesized by using pulsed direct current (DC) reactive magnetron sputtering of Cu targets under Ar atmosphere onto various TiO2 supports. The physiochemical properties of the catalysts were characterized by using inductive coupled plasma spectroscopy (ICP), X-ray diffraction (XRD), UV–Vis spectroscopy, N2 physisorption, transmission electron microscopy (TEM), PL spectroscopy, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of all the catalysts were studied via the photocatalytic reduction of CO2 and H2O to CH4 under UV light irradiation. The Cu/TiO2 catalysts exhibited higher photocatalytic activity than the uncoated TiO2 supports and the ones made using an impregnation technique. The electron trapping of copper species, which prolonged the electron-hole recombination process, promoted photocatalytic activity of the Cu-doped catalysts. Moreover, the specific morphologies of the Cu species deposited on TiO2 supports and the smaller change of bandgap energy of the sputter coated catalysts also resulted in an improvement of photocatalytic activity under UV light irradiation.

Identification of Exciton–Exciton Annihilation in Hematite Thin Films

Hematite, a common type of iron oxide, is a promising material for solar technologies because of its small band gap that allows for solar radiation absorption in the visible region, low toxicity in aqueous solutions, easy synthesis, and natural abundance. However, fast electron–hole recombination has been hampering full applicability of hematite in solar technologies. In this study, we used visible femtosecond transient absorption spectroscopy to investigate the excited-state decay and electron–hole recombination dynamics of nanostructured hematite thin films. By varying the pump excitation fluence and performing global and target data analysis, we identified the presence of nonlinear decay processes during the initial picosecond after photoexcitation, which have a non-negligible contribution at pump fluences of >∼1 mJ/(pulse·cm2). Calculations show exciton–exciton annihilation to be the dominant nonlinear process, with an average rate constant of 7.09 × 10–9 cm3 s–1. Annihilation calculations also allowed us to estimate the annihilation radius to be 2.3 nm, thus explaining the rapid exciton–exciton annihilation in the immediate aftermath of photoexcitation. Probe wavelength-dependent decay dynamics points to excitation energy redistribution and involvement of traps in the recombination dynamics. We finally present a kinetic model, verified by performing target data analysis, showing the rates and channels of the dominant processes involved with electron–hole recombination upon relatively high excitation rates. The extremely fast electron–hole recombination process in hematite is one of the main reasons hindering the full applicability of the material in solar water splitting. Measures to limit these ultrafast recombination processes should, therefore, be incorporated into device fabrication and preparation to further improve the material.

Exploring low-temperature processed a-WOx/SnO2 hybrid electron transporting layer for perovskite solar cells with efficiency >20.5%

Interfacial engineering strategy between the perovskite absorber and the charge transport layer play a vital role in highly efficient perovskite solar cells. Here, we propose an amorphous tungsten oxides/tin dioxide hybrid electron transport layer to effectively block holes through the pinholes and cracks of tin dioxide to indium tin oxide, resulting in promoting charge extraction and hindering electron-hole recombination process at the hetero-interface. Moreover, owing to the higher mobility of amorphous tungsten oxides and formation of cascade energy level sequence between amorphous tungsten oxides and tin dioxide, better electron transport is obtained compared with the traditional electron transport layer. The PSCs based on amorphous tungsten oxides/tin dioxide hybrid electron transport layer shows a better power conversion efficiency of 20.52% than the single tin dioxide electron transport layer. This study guides design strategies of the electron transport layer to enhance the efficiency of the perovskite solar cells by interfacial engineering. Moreover, the entire devices preparation process are finished at a temperature below 150 °C, promising great potential for the practical use in monolithic tandem devices and providing an avenue for the progress of flexible device.

Nanosized Fe3O4 incorporated on a TiO2 surface for the enhanced photocatalytic degradation of organic pollutants

In this work, precipitation and sol-gel mixed procedures were used to prepare a TiO2@Fe3O4 nanocomposite. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) results unmistakably elucidated the tetragonal structure of TiO2 with the cubic structure of Fe3O4. The particle size, interface, and surface area were determined by transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) measurements. The TEM image of the prepared TiO2@Fe3O4 clearly showed that the material is nano-spherical in shape. The BET surface area of the nanocomposite was measured to have a higher value (115.7 m2/g) than those of the TiO2 (65.2 m/g) and Fe3O4 (30.1 m2/g) pure systems because of the synergistic effect and interface between the two different oxides. The absorption edges of the TiO2@Fe3O4 nanocomposites were studied with the UV-abs spectrometer, and the results revealed that the material band gap is 2.70 eV. The chemical composition and dispersion of the nanocomposite system was assessed via energy dispersive X-ray spectroscopy (EDS) along with elemental mapping. The PL spectra of the prepared nanocomposite system indicated a delay of the electron-hole recombination process due to the presence of Fe3O4, thus inducing intermediate states into the TiO2 system. The favourable optical properties of the developed nanocomposites were exploited for the photocatalytic degradation of colourful dyes, such as methylene blue, and methyl orange, as well as of colourless phenol. In addition, their stability and photocatalytic mechanism are explained in detail.

Charge-Transfer-Induced Photoluminescence Properties of WSe2 Monolayer-Bilayer Homojunction.

The charge-transfer process in transition-metal dichalcogenides (TMDCs) lateral homojunction affects the electron-hole recombination process of in optoelectronic devices. However, the optical properties of the homojunction reflecting the charge-transfer process has not been observed and studied. In this work, we investigated the charge-transfer-induced emission properties based on monolayer (1L)-bilayer (2L) WSe2 lateral homojunction with dozens of nanometer monolayer region. On the one hand, the photoluminescence (PL) emission of bilayer WSe2 from the homojunction area blue shifts ∼23 and ∼31 meV for direct and indirect bandgap emission, respectively, compared with the bare WSe2 bilayer region. The blue shift of the emission spectrum in the bilayer WSe2 is ascribed to the decrease in binding energy induced by charge transfer from monolayer to bilayer. On the other hand, the energy shift shows a tendency to increase as the temperature decreases. The energy blue shift is ∼57 meV for direct bandgap emission at 80 K, which is larger than that (∼23 meV) at room temperature. The larger-energy blue shift at low temperature is derived from the larger driving force under larger band offset. Our observations of the unique optical properties induced by efficient charge transfer are very helpful for exploring novel TMDC-based optoelectronic devices.

Effect of the Degree of Inversion on the Photoelectrochemical Activity of Spinel ZnFe2O4

Physicochemical properties of spinel ZnFe2O4 (ZFO) are known to be strongly affected by the distribution of the cations within the oxygen lattice. In this work, the correlation between the degree of inversion, the electronic transitions, the work function, and the photoelectrochemical activity of ZFO was investigated. By room-temperature photoluminescence measurements, three electronic transitions at approximately 625, 547, and 464 nm (1.98, 2.27, and 2.67 eV, respectively) were observed for the samples with different cation distributions. The transitions at 625 and 547 nm were assigned to near-band-edge electron-hole recombination processes involving O2- 2p and Fe3+ 3d levels. The transition at 464 nm, which has a longer lifetime, was assigned to the relaxation of the excited states produced after electron excitations from O2- 2p to Zn2+ 4s levels. Thus, under illumination with wavelengths shorter than 464 nm, electron-hole pairs are produced in ZFO by two apparently independent mechanisms. Furthermore, the charge carriers generated by the O2− 2p to Zn2+ 4s electronic transition at 464 nm were found to have a higher incident photon-to-current efficiency than the ones generated by the O2− 2p to Fe3+ 3d electronic transition. As the degree of inversion of ZFO increases, the probability of a transition involving the Zn2+ 4s levels increases and the probability of a transition involving the Fe3+ 3d levels decreases. This effect contributes to the increase in the photoelectrochemical efficiency observed for the ZFO photoanodes having a larger cation distribution.

Facile sonochemical synthesis and photocatalysis of Ag nanoparticle/ZnWO4-nanorod nanocomposites

A facile sonochemical method was developed to synthesize metallic Ag spherical nanoparticles on the surface of ZnWO4 nanorods by forming heterostructure Ag/ZnWO4 nanocomposites. The Ag/ZnWO4 nanocomposites were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The experimental results showed that fcc metallic Ag nanoparticles were supported on surface of monoclinic sanmartinite ZnWO4 nanorods. The Ag 3d3/2 and Ag 3d5/2 peaks have well-separated binding energies of 6.00 eV, certifying the existence of metallic Ag. The Ag/ZnWO4 nanocomposites were evaluated for photodegradation of methylene blue (MB) induced by ultraviolet–visible (UV-Vis) radiation. In this research, heterostructure 10 wt% Ag nanoparticle/ZnWO4-nanorod composites have the highest photocatalytic activity of 99% degradation of MB within 60 min. The increase in photocatalytic activity was the result of photoinduced electrons in conduction band of ZnWO4 that effectively diffused to metallic Ag spherical nanoparticles and the inhibition of electron–hole recombination process.

First-Principles Understanding of Strong Auger Recombination in Hybrid Perovskites

The radiative recombination coefficient of the hybrid perovskites is as high as in typical direct-gap semiconductors [1], facilitating strong light absorption in solar cells and potentially enabling their application in light-emitting diodes (LEDs). Since LEDs operate at higher carrier densities than solar cells, higher-order electron–hole recombination processes can critically affect their efficiency. We have computed Auger recombination coefficients in the prototypical halide perovskite [2], CH3NH3PbI3 (MAPbI3), using first‐principles calculations. Our computed nonradiative Auger coefficients show that strong Auger recombination may suppress the LED’s efficiency. Fortunately, our insights into the origins of the strong Auger recombination indicate potential avenues for engineering to reduce the effect of Auger recombination. This work was supported by DOE. [1] Zhang, X, et al. ACS Energy Lett. 3, 2329 (2018). [2] Shen, J.-X., et al. Adv. Energy Mater. 8, 1801027 (2018).

Ultrafast photoinduced charge dynamics in colloidal CdSe/CdS quantum dots in toluene

We studied the dynamics of photoinduced charge carriers in core/shell CdSe/CdS quantum dots (QDs) of two sizes, 2.0 and 2.9 nm, in a toluene colloid by femtosecond up-conversion spectroscopy. We observed the luminescence kinetics of QDs excited by 50 fs laser pulses at a wavelength of 385 nm. The modeling of experimental data showed that a 0.5 ps rise of the luminescence intensity corresponds to the process of electron thermalization. The two-exponential luminescence decay with characteristic times in the picosecond range corresponds to populating of two types of traps, which we associate with core and shell defects. Electron–hole recombination process does not affect the shape of the luminescence kinetics in the picosecond range. A comparative analysis indicates that the concentration of defects in 2.0 nm QDs is greater than that in 2.9 nm QDs, while potential wells, which charge carriers eventually escape due to thermal activation, are deeper for 2.9 nm QDs.

Broadband photodetection in wide temperature range: Layer-by-layer exfoliation monitoring of WS2 bulk using microscopy and spectroscopy

Exfoliation of bulk WS2 powder has been conducted by ultrasonication, and its layer by layer peeling is monitored by HRTEM, XRD, UV-Vis, and Raman spectroscopy. HRTEM confirms the peeling process and selected area electron diffraction pattern shows the crystallinity of nanosheets which is in accordance with the X-ray diffraction results. Raman and UV-visible spectroscopies further confirm the exfoliation of WS2 to nanosheets having a few layers. A photodetector developed from a few-layered WS2 film is used for photodetection over wide wavelength and temperature ranges. The detector exhibits the highest sensitivity at 635 nm with a value of 382% at 77 K against a value of 138% at 300 K, while the response and the recovery time are ∼78 ms and ∼40 ms, respectively. Temperature, excitation wavelength, and laser power-dependent studies show the threshold limit of its faithful operation. Temperature-dependent photoresponsivity and sensitivity are explained in terms of the carrier–phonon scattering dependent transport mechanism. The scattering cross-section analysis using the density functional theory model reveals that it is the in-plane and out-of-plane acoustic modes that play a key role in carrier transport, rather than the optical phonons. The influence of atmospheric constituents (N2, O2) on detector performance is checked by a successive exposure to dry N2 and ambient air flow. A 14% reduction in photoresponsivity under O2 exposure is observed and suitable analysis is given in terms of O2 induced enhancement of the electron–hole recombination process, leading to a loss of photogenerated carriers. The sensor's cycling performance remains unaffected even after a prolonged exposure in ambient conditions (55% RH), showing its chemical stability even for long-term use.

Photocatalytic Liquid-Phase Selective Hydrogenation of 3-Nitrostyrene to 3-vinylaniline of Various Treated-TiO2 Without Use of Reducing Gas

In this work, we investigate the effect of TiO2 properties on the photocatalytic selective hydrogenation of 3-nitrostyrene (3-NS) to 3-vinylaniline (3-VA). The P25-TiO2 photocatalysts were calcined at 600–900 °C using different gases (Air, N2, and H2) and characterized by XRD, N2 physisorption, XPS, UV-Vis, and PL spectroscopy. In the photocatalytic hydrogenation of 3-nitrostyrene in isopropanol, the selectivity of 3-vinylaniline of the treated TiO2 was almost 100%. A linear correlation between the 3-NS consumption rate and PL intensity was observed. Among the catalysts studied, P25-700-air, which possessed the lowest PL intensity, exhibited the highest photocatalytic activity due to the synergistic effect that resulted from its high crystallinity and the optimum amount of anatase/rutile phase content, leading to the reduction of the electron-hole recombination process.

Controlled Microwave-Assisted Synthesis of the 2D-BiOCl/2D-g-C3N4 Heterostructure for the Degradation of Amine-Based Pharmaceuticals under Solar Light Illumination.

Designing efficient 2D-bismuth oxychloride (BiOCl)/2D-g-C3N4 heterojunction photocatalysts by the microwave-assisted method was studied in this work using different amounts of BiOCl plates coupled with g-C3N4 nanosheets. The effects of coupling the 2D structure of g-C3N4 with the 2D structure of BiOCl were systematically examined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, X-ray diffraction, photoluminescence (PL), lifetime decay measurement, surface charges of the samples at various pH conditions, and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The prepared photocatalysts were used for the degradation of amine-based pharmaceuticals, and nizatidine was used as a model pollutant to evaluate the photocatalytic activity. The UV–vis DRS and other optical properties indicated the major effect of coupling of BiOCl with g-C3N4 into a 2D/2D structure. The results showed a narrowing in the band gap energy of the composite form, whereas the PL and lifetime analysis showed greater inhibition of the electron–hole recombination process and slightly longer charge carrier lifetime. Accordingly, the BiOCl/g-C3N4 composite samples exhibited an enhancement in the photocatalytic performance, specifically for the 10% BiOCl/g-C3N4 sample. Moreover, the zeta potential of this sample at different pH values was evaluated to determine the isoelectric point of the synthesized composite material. Consequently, the pH was adjusted to match the isoelectric point of the complex materials, which further enhanced the activity. Further degradation of pharmaceuticals was studied under solar light irradiation, and 96% degradation was achieved within 30 min.

Optimizing copper oxide layer on zinc oxide via two-step electrodeposition for better photocatalytic performance in photoelectrochemical cells

The microstructure of copper oxide layer on zinc oxide is optimized via a two-step electrodeposition method to create potential composite electrodes for photoelectrochemical cells. By optimizing the deposition temperature, the microstructure and photocatalytic properties can be fundamentally modified. The strategy includes the potentiostatic deposition of zinc oxide layer in the initial step following galvanostatic deposition of copper oxide at selected bath temperature, including 30, 40, 50, and 60 °C. In all cases, the copper oxide layer deposited at 40 °C significantly improves the photoanodic current density. Also, the microstructure and optoelectrical properties of the composite films are characterized by electron microscopy, impedance spectroscopy, Mott–Schottky, and solar simulation measurements. It is found that variation in copper oxide deposition temperature affects the electron-hole recombination process and photocatalytic performance.

MgAl2O4 both as short and long persistent phosphor material: Role of antisite defect centers in determining the decay kinetics

The present work describes the role of antisite defects centers in determining the phosphor characteristics of MgAl2O4, arising due to inversion nature of the spinel compound. The diverse decay characteristics impart this material both as long persistent bluish phosphor as well as short persistent red phosphors material depending upon the annealing temperature. TL study confirmed the fact that there are several defect centers which acts as electron and hole trap centers inside the band gap. FTIR and DRS study confirmed the presence of antisite defects centers viz. AlMg+ or MgAl−, which act as an electron and hole trap centers and thereby delaying the electron-hole recombination process. Lower inversion nature of this spinel compound at higher annealing temperature results in decay in those defects concentration, as reflected in lifetime values.

Unexpectedly Strong Auger Recombination in Halide Perovskites

AbstractThe emergence of halide perovskites for photovoltaic applications has triggered great interest in these materials for solid‐state light emission. Higher order electron–hole recombination processes can critically affect the efficiency of such devices. In the present work, the Auger recombination coefficients are computed in the prototypical halide perovskite, CH3NH3PbI3 (MAPbI3), using first‐principles calculations. It is demonstrated that Auger recombination is responsible for the exceptionally high third‐order recombination coefficient observed in experiment. The large Auger coefficient is attributed to a coincidental resonance between the bandgap and interband transitions to a complex of higher‐lying conduction bands. Additionally, it is found that the distortions of PbI6 octahedra contribute significantly to the high Auger coefficient, offering potential avenues for materials design.