Halide Perovskite Solar Cells Research Articles

Effects of MgF2 anti-reflection coating on optical losses in metal halide perovskite solar cells

The importance of light management for perovskite solar cells (PSCs) has recently been emphasized because their power conversion efficiency approaches their theoretical thermodynamic limits. Among optical strategies, anti-reflection (AR) coating is the most widely used method to reduce reflectance loss and thus increase light-harvesting efficiency. Monolayer MgF2 is a well-known AR material because of its optimal refractive index, simple fabrication process, and physical and chemical durabilities. Nevertheless, quantitative estimates of the improvement achieved by the MgF2 AR layer are lacking. In this study, we conducted theoretical and experimental evaluations to assess the AR effect of MgF2 on the performance of formamidinium lead-triiodide PSCs. A sinusoidal tendency to enhance the short-circuit current density (J SC) was observed depending on the thickness, which was attributed to the interference of the incident light. A transfer matrix method-based simulation was conducted to calculate the optical losses, demonstrating the critical impact of reflectance loss on the J SC improvement. The predicted J SCs values, depending on the perovskite thickness and the incident angle, are also presented. The combined use of experimental and theoretical approaches offers notable advantages, including accurate interpretation of photocurrent generation, detailed optical analysis of the experimental results, and device performance predictions under unexplored conditions.

Inductive and Capacitive Hysteresis of Current-Voltage Curves: Unified Structural Dynamics in Solar Energy Devices, Memristors, Ionic Transistors, and Bioelectronics

Hysteresis observed in the current-voltage curves of both electronic and ionic devices is a phenomenon where the curve's shape is altered on the basis of the measurement speed. This effect is driven by internal processes that introduce a time delay in the response to an external stimulus, leading to measurements being dependent on the history of the past disturbances. This hysteresis effect has posed challenges, particularly in solution-processed photovoltaic devices such as halide perovskite solar cells, where it significantly complicates the evaluation of performance quality. In other devices, such as memristors and organic electrochemical transistors for neuromorphic applications, hysteresis is an inherent aspect of their functionality, facilitating transitions between different conductivity states. Natural and artificial ionically conducting channels also exhibit pronounced hysteresis, a crucial component for generating action potentials in neurons. In this study, we aim to categorize various forms of hysteresis by identifying shared elements among diverse physical, chemical, and biological conducting systems. Our method involves examining hysteresis from multiple angles, using simplified models that capture essential response types. We analyze system behavior using techniques such as linear sweep voltammetry and impedance spectroscopy and transient currents resulting from small voltage steps. Our investigation reveals two primary hysteresis types based on how current responds to rapid sweep rates: capacitive hysteresis and inductive hysteresis. These terms correspond to the dominant component in the equivalent circuit, determining the transient time response. Remarkably, these concepts provide insights into vastly different systems, spanning solar cells, capacitors, transistors, electrofluidic nanopores, and protein ion channels. The consistency in electrical responses across the different cases enables the identification of the primary cause of hysteresis. We also elucidate the frequency dependence of hysteresis and the stepwise responses of solar cells, illustrating how fundamental relaxations contribute to the overall surplus or deficit of current during extensive voltage sweeps that define the current-voltage curve. Published by the American Physical Society 2024

Passivating A-Site and X-Site Vacancies Simultaneously via N-Heterocyclic Amines for Efficient Cs2AgBiBr6 Solar Cells.

To address the toxicity and stability issues of traditional lead halide perovskite solar cells (PSCs), the development of lead-free PSCs, such as Cs2AgBiBr6 solar cells, is of great significance. However, due to the low defect formation energy of Cs2AgBiBr6, a large number of vacancies, including A-site vacancies and X-site vacancies, form during the fabrication process of the Cs2AgBiBr6 film, which seriously damage the performance of the devices. The traditional phenylethylammonium (PEA) cation, mainly focusing on passivating A-site vacancies, is incapable of reducing X-site vacancies and so results in a limited performance improvement in Cs2AgBiBr6 solar cells. Herein, inspired by the capability of the Lewis base to coordinate with metal cations, a series of N-heterocyclic amines are introduced to serve as a dual-site passivator, reducing A-site and X-site vacancies at the same time. The highest power conversion efficiency of modified Cs2AgBiBr6 solar cells has been increased 36% from 1.10 to 1.50%. Further investigation reveals that the higher electron density of additives would lead to a stronger interaction with metal cations like Ag+ and Bi3+, thus reducing more X-site defects and improving carrier dynamics. Our work provides a strategy for passivating perovskite with various kinds of defects and reveals the connection between the coordination capability of additives and device performance enhancement, which could be instructive in improving the performance of lead-free PSCs.

Recent developments in perovskite materials, fabrication techniques, band gap engineering, and the stability of perovskite solar cells

Organic-inorganic hybrid metal halide perovskite solar cells (PSC) represent a novel class of optoelectronic semiconductors that have garnered significant attention from photovoltaic researchers globally. This is due to their continually improving efficiency, straightforward solution processing methods, use of lightweight and cost-effective materials, and other notable features. The advantageous properties of perovskite materials, such as superior charge transport, tunable band gap, and distinctive electronic structure, contribute to their appeal. Over the past 6 to 7 years, diverse device architectures and fabrication techniques for PSC have emerged, achieving an impressive power conversion efficiency (PCE) of 25.7%. This review article primarily focuses on recent advancements in PSC fabrication techniques, synthesis, device architecture, charge transport mechanisms, band gap engineering, and stability. Additionally, it provides a summary of recently reported materials used in various layers of PSC, including the perovskite layer, as well as electron and hole transport layers. Lastly, the article outlines the challenges faced in the development of PSC, offers recommendations, and suggests potential directions for future research to guide the field forward.

3-Thiophenemalonic Acid Additive Enhanced Performance in Perovskite Solar Cells.

The development of ambient-air-processable organic-inorganic halide perovskite solar cells (OIHPSCs) is a challenge necessary for the transfer of laboratory-scale technology to large-scale and low-cost manufacturing of such devices. Different approaches like additives, antisolvents, composition engineering, and different deposition techniques have been employed to improve the morphology of the perovskite films. Additives that can form Lewis acid-base adducts are known to minimize extrinsic impacts that trigger defects in ambient air. In this work, we used the 3-thiophenemalonic acid (3-TMA) additive, which possesses thiol and carboxyl functional groups, to convert PbI2, PbCl2, and CH3NH3I to CH3NH3PbI3 completely. This strategy is effective in regulating the kinetics of crystallization and improving the crystallinity of the light-absorbing layer under high relative humidity (RH) conditions (30-50%). As a result, the 3-TMA additive increases the yield of the power conversion efficiency (PCE) from 14.9 to 16.5% and its stability under the maximum power point. Finally, we found that the results of this work are highly relevant and provide additional inputs to the ongoing research progress related to additive engineering as one of the efficient strategies to reduce parasitic recombination and enhance the stability of inverted OIHPSCs in ambient environment processing.

High-throughput calculation for the screening of formamidinium halide perovskite for solar cells.

128 organic halide perovskites are systematically investigated using high-throughput first principles calculations where Ge and Sn-based materials are searched. The results revealed that all calculated materials exhibited exothermic reactions. Notably, a correlation between the heat of formation and X-site ions is identified. Six specific compounds, namely FA-Ge-I-I-I, FA-Sn-F-I-I, FA-Sn-Cl-I-I, FA-Sn-Br-Br-I, FA-Sn-Br-I-I, and FA-Sn-I-I-I, where FA stands for formamidinium, are found to have a bandgap ranging from 1.0 to 2.0 eV, characterized by a direct bandgap in their band structure. Electronic structure analysis indicated that the CBM (conduction band minimum) is influenced by the B-site p-orbital, while the VBM (valence band maximum) is influenced by the X-site p-orbitals. This study underscores the capability of high-throughput calculations to unveil hidden trends in perovskite materials, offering an effective approach for the exploration of promising perovskite materials.

An open-cage bis[60]fulleroid as an electron transport material for tin halide perovskite solar cells.

An open-cage bis[60]fulleroid (OC) was applied as an electron transport material (ETM) in tin (Sn) halide perovskite solar cells (PSCs). Due to the reduced offset between the energy levels of Sn-based perovskites and ETMs, the power conversion efficiency (PCE) of Sn-based PSCs with OC reached 9.6% with an open-circuit voltage (VOC) of 0.72 V. Additionally, OC exhibited superior thermal stability and provided 75% of the material without decomposition after vacuum deposition. The PSC using vacuum-deposited OC as the ETM could afford a PCE of 7.6%, which is a big leap forward compared with previous results using vacuum-deposited fullerene derivatives as ETMs.

Measuring metal halide perovskite single cell degradation consistent with module-based conditions

Although a harsher condition, degradation of perovskite solar cells in an open-circuit condition is related to the performance in a quasi-maximum power point condition. Further, shadow masks should be used during illuminated stability studies.

Addressing ambient stability challenges in pure FASnI3 perovskite solar cells through organic additive engineering

In this work we designed and synthesized two new organic additives with different functional groups to evaluate their impact on the performance and stability of tin halide perovskite solar cells.

Crystalline porous materials in perovskite solar cells: a mutually beneficial marriage

Utilization of CPMs across diverse functional layers within Perovskite Solar Cells (PSCs) are systematically classified and analyzed. We scrutinize the correlation between the incorporation of CPMs and the resulting performance of PSC devices.

Toward durable all-inorganic perovskite solar cells: from lead-based to lead-free.

Organic-inorganic metal halide perovskite solar cells (PSCs) have attracted extensive attention from the photovoltaic (PV) community due to their fast-growing power conversion efficiency from 3.8% to 26.7% in only 15 years. However, these organic-inorganic hybrid PSCs suffer from inferior long-term operational stability under thermal and light stress, due to the fragile hydrogen bonds between organic cations and inorganic slabs. This motivates the exploration of more robust all-inorganic alternatives against external stimuli, by substituting inorganic cesium (Cs) cations for volatile organic cations. Despite reinforced ionic interaction between Cs cations and metal halide frameworks, these Cs-based all-inorganic perovskites tend to undergo spontaneous phase transition from photoactive black phases to non-perovskite yellow phases at room temperature, significantly deteriorating their optoelectronic performance. Thus, tremendous efforts have been made to stabilize the black phase of CsPbI3, while the phase instability issue of the tin-based analogue of CsSnI3 has not been resolved yet. This highlight article summarizes the empirical advances in stabilizing the metastable phases of CsPbI3, aiming to provide useful guidelines to accelerate the development of phase-stable CsSnI3 for durable lead-free PV applications. Finally, the remaining challenges and future research opportunities are outlined, providing a road map to realize efficient and durable all-inorganic perovskite solar cells towards practical applications.

Doping strategies for inorganic lead-free halide perovskite solar cells: progress and challenges.

In recent years, remarkable advancements have been achieved in the field of halide perovskite solar cells (PSCs). However, the commercialization of PSCs has been impeded by challenges such as Pb leakage and the instability of hybrid organic-inorganic perovskites (HOIPs). Hence, the future lies in the development of environmentally friendly inorganic lead-free halide perovskites (LFHPs) based on elements like Sn, Ge, Bi, Sb, and Cu, which show great promise for photovoltaic applications. However, LFHP photovoltaic cells still face challenges such as low efficiency, poor film quality, and stability in comparison to HOIPs. These limitations significantly hinder their further development. To address these issues, element doping strategies, including cationic and anionic doping, as well as the use of additives, are frequently employed. These strategies aim to improve film quality, passivate defects, reduce the band gap, and enhance device performance and stability. In this paper, we aim to provide a comprehensive review of the recent research progress in doping strategies for LFHPs.

Evolving bifacial molecule strategy for surface passivation of lead halide perovskite solar cells

We designed new C2- and C3-symmetric molecules for passivating lead halide perovskite solar cells (PSCs). These unique bifacial molecules enable efficient hole transfer, defect passivation, and improved efficiency and stability.

Preparation of two-dimensional perovskite layer by solution method for improving stability of FAPbI<sub>3</sub> perovskite solar cells

Organic-inorganic metal halide perovskite solar cells (PSCs) have been widely studied due to their excellent photoelectric conversion performance, but the inherent chemical instability of CH(NH<sub>2</sub>)<sub>2</sub>PbI<sub>3</sub> (FAPbI<sub>3</sub>) hinders its sustainable development. In particular, the surface interface of the membrane has prominent humidity sensitivity due to lower activation energy, the defect of the surface interface has a strong correlation with the film stability, and the treatment result of the defect is one of the key factors to improve the long-term stability. The FAPbI<sub>3</sub> suffers phase transition from black perovskite phase to yellow non-perovskite phase at room temperature, and the moisture will accelerate this phase transition. Interface engineering is one of the common methods to improve the stability of perovskite solar cells. In addition to interface engineering, there is a strategy of stacking a two-dimensional (2D) perovskite layer on the surface for interface passivation. However, most of the preparation methods of 2D perovskite layer have limitations. In this work, the full solution method and post-treatment mode of annealing are adopted, the hybrid perovskite solar cells of vitamin perovskite are successfully fabricated. The FAPbI<sub>3</sub> perovskite surface is uniformly spin-coated with butylamine iodide (BAI) solution, and the formation of 2D perovskite is driven on the surface of FAPbI<sub>3</sub> perovskite. Due to the passivation of surface interface defects by the 2D perovskite layer, the non-radiative recombination of charge carriers is reduced, greatly improving the carrier lifetime. Because of the hydrophobicity of long chain molecules in 2D perovskite, the long-term stability of the device is significantly improved. Consequently, the unencapsulated device containing 2D perovskite layer remains above 80% after operating at room temperature in ambient air with a relative humidity (RH) of 60% for nearly 1000 hours. The 2D perovskite layer can significantly improve the long-term stability of the film without affecting the charge carrier transport performance. This method of improving the stability of the device by constructing 2D perovskite layer is in line with the requirements and development trend of high-quality perovskite solar cells, and is a strategy with great development potential.

Microstress for metal halide perovskite solar cells: from source to influence and management.

The power conversion efficiency of metal halide perovskite solar cells (PSCs) has increased dramatically in recent years, but there are still major bottlenecks in the commercial application of such materials, including intrinsic instability caused by external stimuli such as water, oxygen, and radiation, as well as local stress generated inside the perovskite and external stress caused by poor interlayer contact. However, some crucial sources of instability cannot be overcome by conventional encapsulation engineering. Among them, the tensile strain can weaken the chemical bonds in the perovskite lattice, thereby reducing the defects formation energy and activation energy of ion migration and accelerating the degradation rate of the perovskite crystal. This review expounds the latest in-depth understanding of microstrain in perovskite film from the thermodynamic sources and influences on the perovskite physicochemical structure and photoelectric performance. Furthermore, it also summarizes the effective strategies for strain regulation and interlayer contact performance improvement, which are conducive to the improvement of photovoltaic performance and internal stability of PSCs. Finally, we present a prospective outlook on how to achieve more stable and higher efficiency PSCs through strain engineering.

Atmospheric Humidity Underlies Irreproducibility of Formamidinium Lead Iodide Perovskites.

Metal halide perovskite solar cells (PSCs) are infamous for their batch-to-batch and lab-to-lab irreproducibility in terms of stability and performance. Reproducible fabrication of PSCs is a critical requirement for market viability and practical commercialization. PSC irreproducibility plagues all levels of the community; from institutional research laboratories, start-up companies, to large established corporations. In this work, the critical function of atmospheric humidity to regulate the crystallization and stabilization of formamidinium lead triiodide (FAPbI3) perovskites is unraveled. It is demonstrated that the humidity content during processing induces profound variations in perovskite stoichiometry, thermodynamic stability, and optoelectronic quality. Almost counterintuitively, it is shown that the presence of humidity is perhaps indispensable to reproduce phase-stable and efficient FAPbI3-based PSCs.

Enhancement in the Rate of CO2 Photoreduction Using Divalent Strontium Cation (Sr2+) Doped TiO2 Nanotube Arrays

The sunlight-assisted conversion of CO2 into portable value-added products has the potential to address both the energy and environmental challenges faced by the world. Therefore, we currently witness intense research activity and substantial progress in the field of CO2 photoreduction. Anatase TiO2 nanotube arrays (TNTAs) formed by electrochemical anodization constitute a well studied semiconductor photocatalyst with excellent optoelectronic properties and photocatalytic behavior [1, 2]. Yet, many aspects related to structure, surface composition, adsorbates, reaction intermediates, rate of reaction, multi-step electron transfer steps, etc. remain poorly understood even for TiO2. This led to our interest in forming surface coatings and bulk nanocomposites of TNTAs with metal oxides of Sr, Mg, Ca, Zn etc, which provide basic sites on the surface of the catalyst for the chemisorption of CO2 molecules. The higher basicity of hydroxyl groups associated with alkaline earth metals generate carbonate and bicarbonate adsorbates which enhance the reactivity of CO2 [3]. Divalent metal cations are also known to influence and modify the crystallographic texture of TiO2 during the annealing treatment step at elevated temperature [4].Here we performed divalent strontium cation (Sr2+) doping of anodically grown TNTAs using two different techniques – an electrochemical cathodic treatment in Sr2+-containing electrolytes and a wet impregnation technique using an aqueoussolution of strontium salts. The X-ray diffraction pattern and Raman spectra indicate the formation of Sr compounds at the TNTA surface. Sr-doping results in modification of the crystallographic texture of anatase phase TNTAs, increased lattice strain, reduced crystal size, and phonon confinement. Subtle changes are observed in the infrared spectra of the CO2 adsorbed on the Sr-doped TNTAs specifying a larger prevalence of monodentate and bidentate carbonate species on the surface. This attributes to the higher alkalinity of surface hydroxyls bound to Sr in comparison to the Ti-bound hydroxyls. In addition to linearly adsorbed CO2, a smaller population of bent CO2 molecules on the surface is observed, which suggests an enhanced stabilization of the carbon dioxide anion radical on the Sr-doped TNTA surfaces. Finally, under AM1.5G one sun illumination, the cathodized TNTAs produce 25 µmolg-1hr-1 whilethe wet impregnated Sr-doped TNTAs produce 17 µmolg-1hr-1 of CO which are nearly 3 and 2 times the amount of CO generated by bare TNTAs (7.7 µmolg-1hr-1) respectively.REFERENCES: Vahidzadeh, Ehsan, et al. "Asymmetric multipole plasmon-mediated catalysis shifts the product selectivity of CO2 photoreduction toward C2+ products." ACS Applied Materials & Interfaces13.6 (2021): 7248-7258.Zeng, Sheng, et al. "Optical control of selectivity of high rate CO2 photoreduction via interband-or hot electron Z-scheme reaction pathways in Au-TiO2 plasmonic photonic crystal photocatalyst." Applied Catalysis B: Environmental267 (2020): 118644.Kwon, Stephanie, et al. "Alkaline-earth metal-oxide overlayers on TiO 2: application toward CO 2 photoreduction." Catalysis Science & Technology6.21 (2016): 7885-7895.Kisslinger, Ryan, et al. "Preferentially oriented TiO2 nanotube arrays on non-native substrates and their improved performance as electron transporting layer in halide perovskite solar cells." Nanotechnology30.20 (2019): 204003.

Effect of Laser Type on Material Characteristics of Halide Perovskite Solar Cell Materials Fabricated Via Laser Molecular Beam Deposition

A key feature of halide perovskite solar cells is the ability to achieve conversion efficiencies in excess of 25% in a solution-coating process under atmospheric pressure [1, 2]. In the solution-coating process, equilibrium chemical reactions that promote crystal growth can produce thin films on the order of μm thickness in a few seconds. On the other hand, physical vapor deposition (PVD) has the advantage of controlled deposition at the molecular level of elements that cannot be obtained by solution reaction, although the deposition rate is relatively slow, generally from sub-nm/s to several tens of nm/s. Laser molecular beam deposition (LMBD), one of the PVD methods, can form thin films by heating and evaporation through infrared (IR) laser irradiation or by ablation through plasma formation by ultraviolet (UV) electron excitation with a pulsed UV laser. LMBD has the advantage of being able to switch the laser beam on and off only on the material surface, resulting in the instantaneous deposition of molecular layers of organic materials with high vapor pressure, as well as of high melting point materials such as inorganic oxides, with minimal cross-contamination. We have been developing halide perovskite solar cell materials based on these advantages in LMBD [3].Experiments with IR laser LMBD were conducted using the following process: synthetic quartz substrates were placed in an ultra-high vacuum chamber with a base vacuum of 2×10-5 Pa. A semiconductor continuous IR laser (wavelength: 808 nm) or an Nd:YAG Q-Switch quadruple-wave UV pulsed laser (wavelength: 266 nm, 10 Hz) was employed to alternately irradiate material targets of PbI2 and MAI, forming CH3NH3PbI3 (MAPbI3) at room temperature. The electron transport layer, using a TiO2 target, and the hole transport layer, using a CuI target, were formed at room temperature. The optical, crystalline, and electrical properties of the films were then characterized by UV-visible spectroscopy, X-ray diffraction (XRD), and Hall measurements, respectively.Four multilayer samples consisting of [PbI2/MAI]×n (n=1, 2, 5, 10) were prepared by IR-LMBD under conditions where the total thickness of PbI2 was fixed at 300 nm. The analysis of the prepared samples by XRD measurements revealed two distinct features: (1) The sample with n = 1 had unreacted PbI2 in addition to MAPbI3, while the samples with n = 2, 5, and 10 only showed MAPbI3, indicating a successful solid-phase reaction. (2) The full width at half maximum and peak position of the diffraction peak for MAPbI3 at 2θ = 14.0° ~ 14.1° varied among the samples, and thus peak separation was performed to determine the presence of both tetragonal (002) and orthorhombic (020) diffraction peaks.In UV-LMBD (or pulsed laser deposition; PLD), a deposition rate of 20 nm/s was attained for the perovskite layer, even under low fluence conditions without lens focusing. However, under the high fluence condition with the lens focusing, the deposition rate dropped significantly to about 0.35 nm/s. The evaluation of the film surface roughness suggested that the effective deposition rate was considerably reduced under the high fluence condition with lens-focusing, due to the excess kinetic energy of the film precursor, which caused re-sputtering on the film surface during deposition.The carrier transport layers were also fabricated by UV-LMBD. The optical and electrical properties of the TiO2 thin film fabricated as the electron transport layer showed an average optical transmittance of 85% and conductivity of 3.2 S/cm at 400 to 800 nm. The CuI thin film fabricated as the hole transport layer was found to have <111> preferential orientation of polycrystalline γ-CuI from the results of X-ray diffraction measurement and to display a conductivity of 24.5 S/cm, hole concentration of 2.7×1019 cm-3, and hole mobility of 6.0 cm2/ (V·s) in hole measurements.We are currently optimizing the process for consistently fabricating the electron transport layer, halide perovskite layer, and hole transport layer in a vacuum through pattern fabrication using a movable shielding mask in the film fabrication area of each layer.[1] T. Miyasaka, A. Kulkarni, G. M. Kim, S. Öz and A. K. Jena, Adv. Energy Mater. 2020, 11902500 (2020).[2] M. Green, E. Dunlop, G. Siefer, M. Yoshita, N. Kopidakis, K. Bothe, X. Hao, Progress in Photovoltaics 31, 3 (2023).[3] K. Kawashima, Y. Okamoto, O. Annayev, N. Toyokura, R. Takahashi, M. Lippmaa, K. Itaka, Y. Suzuki, N. Matsuki and H. Koinuma, Sci. Technol. Adv. Mater. 18, 307 (2017).

Molecular Relays in Nanometer Scale Alumina: Effective Protection Layers for Water-Submersed Halide Perovskite Photocathodes

Halide perovskite (HaP) solar cells have an excellent voltage efficiency (>70%) and a low electron-affinity conduction band minimum, making them prospective candidates to be used as photocathodes in integrated low-cost solar fuel generators. However, halide perovskites are notoriously unstable in aqueous solutions and immediately dissolve upon exposure to liquid water. Ultrathin layers (< 10 nm) of Al2O3 deposited by atomic layer deposition are suitable encapsulants to prevent water ingression but are also electronically insulating. Embedding linear conjugated organic molecules (‘molecular relays’) that transverse the insulating layer enables selective electron transport across the insulating encapsulating layer. The electronic functionality of the embedded molecular relays is verified by conductive probe atomic force microscopy and photo-electrodeposition of metal particles (Pt and Ag) from ethanolic solutions. Lastly, the encapsulated HaP photoelectrodes were submersed in a CO2-saturated aqueous electrolyte and a photocurrent of ~100 µA/cm2 (at ~ -0.32 V vs. Ag/AgCl) was measured. This work demonstrates a way for stabilizing semiconductors in polar and protonic electrolytes as photoelectrodes for the generation of solar fuels.

(Invited) Correlation of Exciton and Charge Carrier Dynamics with the Performance of Metal Halide Perovskite Solar Cells

Perovskite solar cells have been recognized as a newly emerging solar cell with the potential of achieving high efficiency with a low cost fabrication process. In particular, facile solution processed cell fabrication facilitated rapid development of optimum cell structure and composition. Over the last few years, the cell efficiency has exceeded 25%.Highly efficient charge transfer reactions in addition to high charge separation efficiency and swift charge transport with minimum charge recombination are required to improve solar cell performance. Intensive studies have been focused on monitoring photo-induced exciton formation and charge dissociation, charge transport and interfacial charge transfer dynamics including interfacial charge recombination in perovskite solar cells.[1-5] Several parameters have been identified to influence these charge carrier dynamics, and therefore the solar cell performance.[1-5] Clarifying these parameters is extremely important to understand the charge transfer mechanisms to further improve solar cell performance.In this presentation, we will present parameters controlling charge dissociation in metal halide perovskites and their charge separation and recombination dynamics at the perovskite interfaces employing a series of transient absorption and emission spectroscopies. Correlation of the key parameters controlling the exciton and charge carrier dynamics with the solar cell performance will be discussed [1-5].This work was partly supported by JSPS KAKENHI Grant (19H02813) and (22H02182), and the Collaborative Research Program of Institute for Chemical Research, Kyoto University (grant number 2023-45 and 2022-99), Japan. We would like to acknowledge supports from the Australia-Japan Foundation for the international collaborative project. We also acknowledge supports from ARC LIEF fund (LE200100051 and LE170100235), Australia and School of Engineering in RMIT University, and Forefront Research Center, Faculty of Science at Osaka University.