Modeling of a Sn-Based HTM-Free Perovskite Solar Cell Using a One-Dimensional Solar Cell Capacitance Simulator Tool

Tin(Sn)-based perovskite solar cells(PSCs)have received increasing attention in the domain of photovoltaics due to their environmentally friendly nature.In this paper,numerical modeling and simulation of hole transport material(HTM)-free PSC based on methyl ammonium tin triiodide(CH_(3) NH_(3) SnI_(3))was performed using a one-dimensional solar cell capacitance simulator(SCAPS-1D)software.The eff ect of perovskite thickness,interface defect density,temperature,and electron transport material(ETM)on the photovoltaic performance of the device was explored.Prior to optimization,the device demonstrated a power conversion effi ciency(PCE)of 8.35%,fi ll factor(FF)of 51.93%,short-circuit current density(J_(sc))of 26.36 mA/cm 2,and open circuit voltage(V_(oc))of 0.610 V.Changing the above parameters individually while keeping others constant,the obtained optimal absorber thickness was 1.0μm,the interface defect density was 1010 cm-2,the temperature was 290 K,and the TiO 2 thickness was 0.01μm.On simulating with the optimized data,the fi nal device gave a PCE of 11.03%,FF of 50.78%,J_(sc) of 29.93 mA/cm 2,and V_(oc) of 0.726 V.Comparing the optimized and unoptimized metric parameters,an improvement of~32.10%in PCE,~13.41%in J_(sc),and~19.02%in V_(oc) were obtained.Therefore,the results of this study are encouraging and can pave the path for developing highly effi cient PSCs that are cost-eff ective,eco-friendly,and comparable to state-of-the-art.

Advances in Sn-Based Catalysts for Electrochemical CO_(2) Reduction

The increasing concentration of CO2 in the atmosphere has led to the greenhouse effect,which greatly affects the climate and the ecological balance of nature.Therefore,converting CO2 into renewable fuels via clean and economical chemical processes has become a great concern for scientists.Electrocatalytic CO2 conversion is a prospective path toward carbon cycling.Among the different electrocatalysts,Sn-based electrocatalysts have been demonstrated as promising catalysts for CO2 electroreduction,producing formate and CO,which are important industrial chemicals.In this review,various Sn-based electrocatalysts are comprehensively summarized in terms of synthesis,catalytic performance,and reaction mechanisms for CO2 electroreduction.Finally,we concisely discuss the current challenges and opportunities of Sn-based electrocatalysts.

Electrical Transport Properties of Type-Ⅷ Sn-Based Single-Crystalline Clathrates (Eu/Ba)8Ga16Sn30 Prepared by Ga Flux Method

Single-crystalline samples of Eu/Ba-filled Sn-based type-Ⅷ clathrate are prepared by the Ga flux method with different stoichiometric ratios. The electrical transport properties of the samples are optimized by Eu doping. Results indicate that Eu atoms tend to replace Ba atoms. With the increase of the Eu initial content, the carrier density increases and the carrier mobility decreases, which leads to an increase of the Seebeck coefficient. By contrast, the electrical conductivity decreases. Finally, the sample with Eu initial content of x = 0.75 behaves with excellent electrical properties, which shows a maximal power factor of 1.51 mW·m^-1K^-2 at 480K, and the highest ZT achieved is 0.87 near the temperature of 483K.

Advances in Sn-based oxide catalysts for the electroreduction of CO_(2) to formate

The excessive consumption of fossil fuels increases carbon dioxide(CO_(2))emissions,and the consequent greenhouse effect resulting from higher levels of this gas in the atmosphere has a significant impact on the environment and climate.This has necessitated the development of environmentally friendly and efficient methods for CO_(2)conversion.The carbon dioxide electroreduction reaction(CO_(2)RR),which is driven by electricity generated by renewable energy sources(e.g.,wind and solar)to convert CO_(2)into value-added fuels or chemicals,is regarded as a promising prospective path toward carbon cycling.Among the various products,formate,with its relatively simple preparation process,has broad application prospects,and can be used as fuel,hydrogen storage material,and raw material for downstream chemicals.Sn-based oxide electrocatalysts have the advantages of being inexpensive and nontoxic.In addition,these catalysts offer high product selectivity and are regarded as promising catalysts for the electrochemical reduction of CO_(2)to formate.In this review,we first clarify the reaction mechanisms and factors that influence the reduction of CO_(2)to formate,and then provide some examples of technologies that could be used to study the evolution of catalysts during the reaction.In particular,we focus on traditional Sn-based oxides(SnO_(2))and novel Sn-based perovskite oxides that have been developed for use in the field of CO_(2)RR in recent years by considering their synthesis,catalytic performance,optimization strategies,and intrinsic principles.Finally,the current challenges and opportunities for Sn-based oxide electrocatalysts are discussed.The perspectives and latest trends presented in this review are expected to inspire researchers to contribute more efforts toward comprehensively optimizing the performance of the CO_(2)RR to produce formate.

High-member low-dimensional Sn-based perovskite solar cells

Sn-based perovskites are promising thin-film photovoltaic materials for their ideal bandgap and the eco-friendliness of Sn,but the performance of Sn-based perovskite solar cells is hindered by the short carrier diffusion length and large defect density in nominally-synthesized Sn-based perovskite films.Herein we demonstrate that a long carrier diffusion length is achievable in quasi-2D Sn-based perovskite films consisting of high-member low-dimensional Ruddlesden-Popper(RP)phases with a preferred crystal orientation distribution.The key to the film synthesis is the use of a molecular additive formed by phenylethylammonium cations and optimally mixed halide-pseudohalide anions,which favorably tailors the quasi-2D Sn-based perovskite crystallization kinetics.The high-member RP film structure effectively enhances device short-circuit current density,giving rise to an increased power conversion efficiency(PCE)of 14.6%.The resulting device demonstrates a near-unity shelf stability upon1,000 h in nitrogen.A high reproductivity is also achieved with a count of 50 devices showing PCEs within a narrow range from minimum 13.0%to maximum 14.6%.

Realizing ultra-pure red emission with Sn-based lead-free perovskites

Light-emitting diodes(LEDs)are key for the development of next-generation displays for ultra-high-definition television.Alternative materials beyond organic LEDs are required to meet the color purity standards,while retaining low processing cost and environmental friendliness.Liang and colleagues report in Advanced Science that two-dimensional(2D)tin halide perovskite—efficiently stabilized by H3PO2 incorporation—has great promise for ultra-pure red LEDs.

A novel Sn-based coordination polymer with high-efficiency and ultrafast lithium storage

Recently,Coordination Polymers(CPs)have been widely utilized as energy storage materials for reversible Lithium-Ion Batteries(LIBs)benefiting from their tunable building blocks and adjusted electrochemical properties.However,the unsatisfied electrochemical behavior of CPs with poor conductivity and sluggish ion transport kinetics is still a bottle-neck for their large-scale energy storage applications in LIBs.Herein,we display the rational fabrication of a conductive Sn-based coordination polymer(Sn-DHTPA)via judiciously choosing suitable building units.The Sn-DHTPA is employed as anode for LIBs,exhibiting superior reversible storage capacity of 1142.6 m A h g^(-1) at 0.1 A g^(-1) after 100 cycles and impressive rate storage capability of 287.7 m A h g^(-1)at 20 A g^(-1).More importantly,a robust cycling performance of 205.5 m A h g^(-1) at an extra-high current density of 20 A g^(-1) are observed without remarkable capacity-fading up to1000 cycles.The behavior superiority of Sn-DHTPA is related to its advanced architecture with abundant lithium storage sites,high electrical conductivity and rapid lithium transport.A series of ex-situ characterizations reveal that the impressive lithium storage capacity is contributed by the redox active sites of both the aromatic linker and metal center related to in-situ generated metallic nanoparticles dispersed in the skeleton.

Reductive ionic liquid-mediated crystallization for enhanced photovoltaic performance of Sn-based perovskite solar cells

Tin(Sn)-based perovskite solar cells(PSCs)have recently made inspiring progress,and certified power conversion efficiency(PCE)has reached impressive value of 14.8%.However,it is still challenging to realize efficient and stable 3D Sn-based PSCs due to the fast crystallization and easy Sn^(2+)oxidation of Sn-based perovskite.Herein,we reported the utilization of a reductive ionic liquid,methylamine formate(MAFa),to drive the controlled crystallization process and suppress Sn^(2+)oxidation of FASnI_(3)perovskite film.The coordination of C=O and Sn^(2+)and the hydrogen bonding of N-H···I between the MAFa and FASnI_(3)precursors are shown to be responsible for retarding the crystallization of FASnI_(3)during film-forming process,which promotes the oriented growth and reduced defect traps of the film.Moreover,the strong reducibility of–CHO groups in Fa−suppresses the oxidation of Sn^(2+)in the film.As a result,MAFa-modified 3D PSCs device could reach champion PCE of up to 8.50%,which is enhanced by 26.11%compared to the control device with PCE of 6.74%.Most importantly,the MAFa-modified device shows much improved stability compared to the control device under same conditions without encapsulation.This work adds key building blocks for further boosting the PCE and stability of Sn-based PSCs.

Effects of Cu addition on growth of Au-Sn intermetallic compounds at Sn-xCu/Au interface during aging process

The growth of Au-Sn intermetallic compounds(IMCs) is a major concern to the reliability of solder joints in microelectronic,optoelectronic and micro-electronic-mechanical system(MEMS) which has a layer of Au metallization on the surface of components or leads.This paper presented the growth behavior of Au-Sn IMCs at interfaces of Au metallization and Sn-based solder joints with the addition of Cu alloying element during aging process,and growth coefficients of the Au-Sn IMCs were calculated.Results on the interfacial reaction between Sn-xCu solders and Au metallization during aging process show that three layers of Au-Sn IMCs including AuSn,AuSn2 and AuSn4 formed at the interface region.The thickness of each Au-Sn IMC layer vs square root of aging time follows linear relationship.Calculation of the IMC growth coefficients shows that the diffusion coefficients decrease with the addition Cu elements,which indicates that Cu addition suppresses the growth of Au-Sn IMCs layer.

Carbon-coated hybrid crystals with fast electrochemical reaction kinetics for ultra-stable and high-load sodium-ion batteries

Owing to its high theoretical capacity and low cost,Sn has attracted significant attention in sodium-ion batteries.However,the slow kinetics of electrochemical reactions and the rapid decay of capacity resulting from drastic changes in the volume of Sn,as well as persistent side reactions between Sn and the organic electrolyte during the(de)sodium process,have limited its commercialization.To improve the electrochemical performance of Sn-based materials,the bottom-up method is normally used to prepare carbon-coated nanoparticles.However,its complex preparation processes and harsh conditions make it unsuitable for practical applications.Herein,a carbon-coated hybrid crystal composite(Sn/SnO_(x)@C)was prepared using an up-bottom method with commercial Sn/SnO nanoparticles.Various effects accelerate the electrochemical kinetics and inhibit the coarsening of Sn crystals.The Sn/SnO_(x)@C composite electrode exhibited capacity retention of 80.7%even after approximately 1000 cycles(360.4 mAh·g^(−1)) at a current density of 1 A·g^(−1).The high-load Na_(3)V_(2)(PO4)3||Sn/SnO_(x)@C full cell presents a capacity retention rate of 91.7%after 150 cycles at the current density of 0.5 A·g^(−1).This work may significantly accelerate the commercialization of the Sn/SnO_(x)@C composite in sodium-ion batteries with high energy density.

温度调控制备锡或二氧化锡@中空多孔碳纳米纤维电极用于个性化定制锂离子电池

锂离子电池广泛应用于电动汽车、混合动力汽车、便携式电子设备等储能系统,但由于电荷在活性材料中传输缓慢以及活性材料易粉碎等缺点,开发同时具有高容量以及快充性能的电极材料仍然是一个极大的挑战.针对这一问题,本文通过温度调控将SnO_(2)量子点或Sn纳米团簇均匀负载在中空多孔碳纳米纤维(HPCNFs)的内部,用于制备个性化定制锂离子电池.一方面,高度互联的碳纳米纤维形成三维网络,加快了电子传输,提高了电子导电性.另一方面,中空多孔结构缩短了锂离子传输路径,促进了锂离子的快速扩散,同时,抑制了Sn和SnO_(2)的体积膨胀.由于具有较高的锂离子吸附性能以及快的离子扩散速率,低碳化温度下(450℃)合成的SnO_(2)@HPCNFs复合电极在0.1 A g^(-1)的小电流密度下具有较高的放电比容量(899.3 mA h g~(-1)).此外,由于在大的电流密度下,Sn的大孔结构能够储存更多的锂离子,以及具有较高的电子电导率,因此,高碳化温度下(850℃)制备的Sn@HPCNFs复合电极展现出优异的快充性能,同时,在5 A g^(-1)(~10 C)的高电流密度下具有238.8 mA h g^(-1)的放电容量.本文通过调控碳化温度来研究SnO_(2)和Sn电极之间的电化学行为,为构建高性能储能器件提供了新的思路.

Double core-shell nanostructured Sn-Cu alloy as enhanced anode materials for lithium and sodium storage

Sn-based alloy materials are considered as a promising anode candidate for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs),whereas they suffer from severe volume change during the discharge/charge process.To address the issue,double core-shell structured Sn-Cu@SnO2@C nanocomposites have been prepared by a simple co-precipitation method combined with carbon coating approach.The double core-shell structure consists of Sn-Cu multiphase alloy nanoparticles as the inner core,intermediate SnO2 layer anchored on the surface of Sn-Cu nanoparticle and outer carbon layer.The Sn-Cu@SnO2@C electrode exhibits outstanding electrochemical perfor-mances,delivering a reversible capacity of 396 mA·h·g^-1 at 100 mA·g^-1 after 100 cycles for LIBs and a high initial reversible capacity of 463 mA·h·g^-1 at 50 mA·g^-1 and a capacity retention of 86% after 100 cycles,along with a remarkable rate capability(193 mA·h·g^-1 at 5000 mA·g^-1)for SIBs.This work provides a viable strategy to fabricate double core-shell structured Sn-based alloy anodes for high energy density LIBs and SIBs.

Efficient and stable Ruddlesden-Popper layered tin-based perovskite solar cells enabled by ionic liquid-bulky spacers

The crucial component,bulky spacers,in two-dimensional Ruddlesden-Popper(2 DRP)layered tin(Sn)perovskites are highly limited by halide ammonium salts,leading to the insufficient control of complex crystallization process due to the limited interaction between bulky spacers and 2 DRP perovskite frameworks.Here,we report an ionic liquid-bulky spacer,butylammounium acetate(BAAc O),for constructing efficient and stable 2 DRP Sn-based perovskite solar cells(PSCs).In contrast to the traditional halide ammonium bulky spacer,butylammounium iodide(BAI),the Ac O^(-)-functional group in BAAc O has a strong interaction with formamidine ions(FA^(+))and Sn2+.The inter-component interaction allows the formation of controllable intermediates for the favorable growth of smooth,dense,and highly oriented perovskite films.A PSC with power conversion efficiency of 10.36%(7.16%for BAI)is achieved,which is the highest report,along with improved stability with~90%retained after~600 h storage in N_(2) atmosphere without any encapsulation.

Phase-boundary regulation boosting electrochemical reactivity of tin-based anodes for magnesium-ion batteries

Tin(Sn)-based materials are promising anodes for magnesium-ion batteries(MIBs) owing to their low reaction voltages, high theoretical specific capacities and good compatibility with conventional electrolytes. However, relatively arduous alloying reaction and sluggish diffusion kinetics limit their practical applications. Herein, we proposed a general strategy to regulate the electrochemical reactivity and performance of Sn-based anodes for Mg storage through the introduction of the second phase and phase boundary. The biphase Sn–Al, Sn–Pb and Sn–Zn O films were further fabricated via magnetron co-sputtering. Taking Sn–Al as an example, it has been revealed that the introduction of Al can effectively stimulate the electrochemical reaction of Sn with Mg in either nanoscale or bulk through combining experiments with density-functional theory calculations. Specially, the rolled Sn–Al electrode exhibits superior long-term stability over 5,000 cycles. Additionally, the Mg-storage mechanism of the Sn–Al electrode was investigated by operando X-ray diffraction. The Sn–Al anodes also demonstrate good compatibility with simple Mg-salt-based electrolytes like Mg(TFSI)2in full cells. More importantly, it has been authenticated that the activation effect of second phase and phase boundary to Sn is also applicable to Pb and Zn O. Our findings may provide a favorable reference for the development of alloy-type anodes for MIBs.

Effect of VO4^3- Substitution on the Electrochemical Properties of a LiSn2（PO4）3 Anode Material

VO4^3- anion was used to partially substitute for PO43 in the Nasicon compound of LiSn2（PO4）3 via a sol-gel method. XRD analysis revealed that the VO4^3-substituted samples did not have a single LiSn2（PO4）3 phase, and some secondary phases like SnO2 and SnP2O7 appeared. Introduction of the VO4^3- anion did not prevent the LiSn2（PO4）3 compound from decomposing during the initial lithiation; however the VO4^3- anion substitution remarkably enhanced the rate capability and cycling performance of the products because they reduced the charge transfer hnpedance, increased the lithium ion diffusion, and strengthened the role of the Li3PQ matrix due to the precipitation of the Li3V04 phase, Of the substituted samples, the sample with a nominal composition of LiSn2（PO4）2.5（VO4）0.5 delivered a capacity of 449.2 mA-h/g at a rate of 0.25 C after 25 cycles and 373.8 mA.h/g at 2 C rate. Those values surpassed some previous reports on LiSn2（PO4）3 and the LiSnz（PO4）3/C composites. Accordingly, the partial substitution of phosphorus by vanadium in LiSn2（PO4）3 is a feasible technique to remarkably improve its electrochemical properties.

Tin Oxide and Carbon Composite (Sn_6O_4(OH)_4 /AG) as the Anode in a Lithium Ion Battery

A tin oxide and carbon composite （Sn6O4（OH）4/AG） with a Sn content of 0.15-0.30 was prepared by chemical deposition at normal pressures and temperatures. The structures of the artificial graphite （AG）, the Sn6O4（OH）4, and the Sn6O4（OH）4JAG were analyzed using X-ray diffraction. The electrochemical lithiation was investigated by measuring the galvanostatic charge and discharge ratio. The electrochemical capacities of the three materials during the first discharge were 310 mAh/g （AG）, 616 mAh/g （Sn6O4（OH）4/AG）, and 1090 mAh/g （Sn6O4（oa）4）. The discharge capacity of the Sn6O4（OH）4/AG was larger than the simple sum of the capacities provided by AG and Sn6O4（OH）4 with the same content. The cyclic performance of Sn6O4（OH）4/AG was also better than that of Sn6O4（OH）4 for voltages of 0 to 3 V. The results imply that the interaction between Sn and C in Sn6O4（OH）4/AG is very strong and effectively inhibits the volume expansion of the Sn.