A short overview of the lead iodide residue impact and regulation strategies in perovskite solar cells

Lead iodide(PbI2) is a vital raw material for preparing perovskite solar cells(PSCs),and it not only takes part in forming the light absorption layer but also remains in the grain boundary as a passivator.In other words,the PbI2 content in the precursor and as formed film will affect the efficiency and stability of the PSCs.With moderate residual PbI2,it passivates the bulk/surface defects of perovskite,reduces the interfacial recombination,promotes the perovskite stability,minimizes the device hysteresis,and so on.Deficient PbI2 residue will reduce the interfacial passivation effect and device performance.In addition to facilitating the non-radiative recombination,over PbI2 residue can also lead to electronic insulation in the grain boundary and deteriorate the device performance.However,the impact and regulation of PbI2 residue on the device performance and stability is still not fully understood.Herein,a comprehensive and detailed review is presented by discussing the PbI2 residue impact and its regulation strategies(i.e., elimination,facilitation and conversion of the residue PbI2) to manipulate the PbI2 content,distribution and forms.Finally,we also show future outlooks in this field,with an aim to help further the progression of high-efficiency and stable PSCs.

Highly Weak-light Sensitive and Dual-band Switchable Photodetector Based on CuI/Si Unilateral Heterojunction

In recent years,copper iodide(CuI)is an emerging p-type wide bandgap semiconductor with high intrinsic Hall mobility,high optical absorption and large exciton binding energy.However,the spectral response and the photoelectric conversion efficiency are limited for CuI-based heterostructure devices,which is related to the difficulty in fabrication of high-quality CuI thin films on other semiconductors.In this study,a p-CuI/n-Si photodiode has been fabricated through a facile solid-phase iodination method.Although the CuI thin film is polycrystalline with obvious structural defects,the CuI/Si diode shows a high weak-light sensitivity and a high rectification ratio of 7.6×10^(4),indicating a good defect tolerance.This is because of the unilateral heterojunction behavior of the formation of the p^(+)n diode.In this work,the mechanism of photocurrent of the p^(+)n diode has been studied comprehensively.Different monochromatic lasers with wavelengths of 400,505,635 and 780 nm have been selected for testing the photoresponse.Under zero-bias voltage,the device is a unilateral heterojunction,and only visible light can be absorbed at the Si side.On the other hand,when a bias voltage of-3 V is applied,the photodiode is switched to a broader“UV-visible”band response mode.Therefore,the detection wavelength range can be switched between the“Visible”and“UV-visible”bands by adjusting the bias voltage.Moreover,the obtained CuI/Si diode was very sensitive to weak light illumination.A very high detectivity of 10^(13)-1014 Jones can be achieved with a power density as low as 0.5μW/cm^(2),which is significantly higher than that of other Cu-based diodes.These findings underscore the high application potential of CuI when integrated with the traditional Si industry.

Copper-mediated 1,4-conjugation reaction of functionalized alkylzinc iodides with derivatives of β-nitrostyrene

Functionalized alkylzinc iodides will undergo 1,4-conjugation reaction with derivatives of β-nitrostyrene in the presence of Cu(OAc)2/LiCl to afford a polyfunctional nitro-compound in high yield.

Addition of Per(poly)fluoroalkyl Iodides to vinyl Cyclopropane Derivatives: Synthesis of Fluoroalkyl Substituted γ,δ-Unsaturated Carbonyl Compounds

In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.

STUDIES ON POLYHALOALKANES Ⅳ. THE REACTION OF POLYFLUOROALKYL IODIDES WITH SILVER(I) SALTS

The conversion of polyfluoroalkyl iodides into the corresponding carboxylic acids by the reaction with silver (I) salts is described.

A SIMPLE ACCESS TO UNSOLVATED MONOMERIC COMPLEXES OF EARLY LANTHANIDE IODIDES(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)VIA THE REACTION OF[(CH_3OCH_2CH_2C_5H_4)_2LnCl]_2 WITH NaI AND X-RAY CRYSTAL STRUCTURE OF THE LANTHANUM COMPLEX

(CH_3OCH_2CH_2C_5H_4)_2LnI(Ln=La,Nd)complexes have been synthesized by the reaction between NaI and[(CH_3OCH_2CH_2C_5H_4)_2LnCl]2 in THF;A single crystal X-ray study has shown that the lanthanum complex is an unsolvated monomer with lanthanum(Ⅲ)in a trigonal bipyramidal coordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.

CuI-catalyzed Synthesis of Aryl Thiocyanates from Aryl Iodides

An operationally simple and inexpensive catalyst system was developed for the cross coupling of potassium thiocyanate with aryl iodides by using CuI as catalyst, 1, 10-phenanthroline as ligand, and tetraethylammonium iodide as activator. The procedure is applicable for the synthesis of diverse aryl thiocyanates without any exotic, poisonous reagents.

Remarkable rate acceleration of SmI3-mediated iodination of acetates of Baylis-Hillman adducts in ionic liquid: facile synthesis of (Z)-allyl iodides

Stereoselective transformation of Baylis-Hillman acetates I into corresponding （Z）-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate （[bmim]BF4） was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford （Z）-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.

Solid-phase synthesis of (Z)-allyl iodides from 3-acetoxy-2-methylene-alkanoates with recyclable polymer-supported selenium bromide

Reaction of polystyrene-supported lithium selenide with 3-acetoxy-2-methylene-alkanoates afforded the corresponding allyl selenide resins and subsequent cleavage from the polymer by treating with methyl iodide to furnish （Z）-allyl iodides in good yields and high purities. The polymeric selenium reagent can be regenerated and reused. So it is a environmentally benign reagent.

STUDY ON Cp_2TiCl_2/Fe-INITIATED ADDITION OF 2-HALOTETRAFLUOROETHYL IODIDES TO ALKYNES AND ALKENES

Initiated by CP_2TiCl_2/Fe redox system,2-halotetrafluoroethyl iodides readily reacted with alkynes or alkenes to give 1:1 adducts in good to excellent yields.

ORGANOPHOSPHINE INITIATED REACTION OF PERFLUOROALKYL IODIDES WITH ALKENES

perfluoroalkyl iodides reacted with alkenes in acetonitrile solu- tion containing catalytic amount of organophosphine under mild condition to give the corresponding adducts in moderate to good yields.Reaction was shown to involve a free radical mechanism.

Algebraic Properties for Molecular Structure of Magnesium Iodide

As an inorganic chemical,magnesium iodide has a significant crystalline structure.It is a complex and multifunctional substance that has the potential to be used in a wide range of medical advancements.Molecular graph theory,on the other hand,provides a sufficient and cost-effective method of investigating chemical structures and networks.M-polynomial is a relatively new method for studying chemical networks and structures in molecular graph theory.It displays numerical descriptors in algebraic form and highlights molecular features in the form of a polynomial function.We present a polynomials display of magnesium iodide structure and calculate several M-polynomials in this paper,particularly the M-polynomials of the augmented Zagreb index,inverse sum index,hyper Zagreb index and for the symmetric division index.

Efficient solar fuel production enabled by an iodide oxidation reaction on atomic layer deposited MoS_(2)

Oxygen evolution reaction(OER)as a half-anodic reaction of water splitting hinders the overall reaction efficiency owing to its thermodynamic and kinetic limitations.Iodide oxidation reaction(IOR)with low thermodynamic barrier and rapid reaction kinetics is a promising alternative to the OER.Herein,we present a molybdenum disulfide(MoS_(2))electrocatalyst for a high-efficiency and remarkably durable anode enabling IOR.MoS_(2)nanosheets deposited on a porous carbon paper via atomic layer deposition show an IOR current density of 10 mA cm^(–2)at an anodic potential of 0.63 V with respect to the reversible hydrogen electrode owing to the porous substrate as well as the intrinsic iodide oxidation capability of MoS_(2)as confirmed by theoretical calculations.The lower positive potential applied to the MoS_(2)-based heterostructure during IOR electrocatalysis prevents deterioration of the active sites on MoS_(2),resulting in exceptional durability of 200 h.Subsequently,we fabricate a two-electrode system comprising a MoS_(2)anode for IOR combined with a commercial Pt@C catalyst cathode for hydrogen evolution reaction.Moreover,the photovoltaic–electrochemical hydrogen production device comprising this electrolyzer and a single perovskite photovoltaic cell shows a record-high current density of 21 mA cm^(–2)at 1 sun under unbiased conditions.

Efficient Environment-friendly Lead-free Tin Perovskite Solar Cells Enabled by Incorporating 4-Fluorobenzylammonium Iodide Additives

Development of tin(Sn)-based perovskite solar cells(PSCs)largely lags behind that of lead counterparts due to fast crystallization process of Sn perovskite and numerous defects in both bulk and surface of Sn perovskite films.Herein,this work reports a facile strategy of introducing 4-fluorobenzylammonium iodide(FBZAI)as additives into Sn perovskite precursor to synergistically modulate the roles of benzylamine and fluorine in Sn-based PSCs.Incorporation of FBZAI can increase crystallinity,passivate defects,and inhibit the oxidation of Sn^(2+),leading to suppression of nonradiative recombination and enhancement of charge transport and collection in devices.As a result,the best-performing Sn-based PSC with the FBZAI additive achieves the maximum PCE of 13.85%with the enhanced fill factor of 77.8%and open-circuit voltage of 0.778 V.Our unencapsulated device exhibits good stability by maintaining 95%of its initial PCE after 160 days of storage.

Treating CsPbI_(3) Perovskite with Pyrrolidinium Iodide to Improve the Performance of Perovskite Solar Cells

All-inorganic CsPbI_(3) perovskite has attracted wide attention due to its desirable optical bandgap(Eg:∼1.7 eV)as well as high chemical stability.Nevertheless,the photovoltaic performance of CsPbI_(3) perovskite solar cells(PSCs)was limited by severe nonradiative charge recombination due to high defect density at the grain boundary and surface of perovskitefilms.To address this issue,a pyrrolidinium iodide(PyI)molecule was introduced to modify the surface and grain boundary of CsPbI_(3) perovskitefilms to passivate defects,which improves the quality of CsPbI_(3) perovskitefilms as well as induces the generation of a quasi-2D Py_(2)CsPb_(2)I_(7) capping layer between per-ovskite layer and hole transport layer.Such quasi-2D Py_(2)CsPb_(2)I_(7) capping layer optimizes interface contact between CsPbI_(3) perovskite layer and hole transport layer and blocks the electron transfer from CsPbI_(3) perovskite photoactive layer to the hole transport layer.As a result,the performance of CsPbI_(3) PSCs is well improved to 17.87%for power conversion efficiency(PCE)with an ultra-high fill factor(FF)of 0.84.In addition,the PyI mole-cule modified CsPbI_(3) perovskite devices exhibit excellent stability,which remains its initial PCE almost unchanged after aging for 35 days under the dry air atmosphere(temperature:20℃–30℃,control relative humid-ity(RH):<10%).

PI法和Annexin V/PI法检测蓝舌病毒HbC_3诱导人肝癌细胞的凋亡

利用流式细胞仪比较PI法和AnnexinV/PI法检测不同时间人肝癌细胞感染蓝舌病毒HbC3的凋亡率分析。结果:PI法在24h、36h、48h的凋亡率分别为10.8±3.05、21.7±6.28、28.3±10.6;AnnexinV/PI法的凋亡率分别为20.42±3.70、49.3±8.11、79.6±11.5。二种方法及不同时间感染病毒细胞的凋亡率之间有显著差异(P<0.01)。证明了AnnexinV/PI法能特异地、准确地检出早期凋亡的细胞、继发性坏死的细胞,BTV-HbC3诱导Hep-3B细胞凋亡是致肿瘤细胞病变、死亡的重要表现形式之一。

Transfection of the Human Sodium/Iodide Symporter(NIS) Gene with Liposomes and the Expression of the NIS Protein in Human Lung A549 Cancer Cells

OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided into an experimental group transfected with a recombinant pcDNA3-hNIS plasmid and a control group transfected only with a pcDNA3 plasmid. The recombinant plasmid vector encoding the hNIS gene （pcDNA3-hNIS） was amplified, purified and identified. The hNIS gene was followed by DNA sequencing. A Western blot and an immunohistochemical assay were applied to detect the hNIS protein expression in the transfected human lung A549 cancer cells. RESULTS Restriction enzyme digestion and DNA sequencing results showed the size and direction of the inserted gene in the recombinant pcD- NA3-hNIS plasmid was correct. The Western blot method and immunohistochemical analysis showed a positive NIS protein expression in the experimental group. The NIS protein was detected mainly in the cell membranes showing a positive rate up to 70.6% with no expression of the NIS protein in the control group. There was a significant difference between two groups （P=0.000）. CONCLUSION The hNIS gene was transfected effectively into human lung A549 cancer cells mediated by Lipofectamine 2000, and was expressed with its protein in vitro.

STUDY ON THE INFRARED TRANSMITTING As_2Te_3-BASED CHALCOHALIDE GLASSES

This paper reports the formation and some properties of a new class of chalcohalide glasses in the As2Tef iodide systems. The As2Te3-Pb12, As2Te3-HgI2, As2Te3-CitI and As2Te3-AgI systems can form stable bulk glasses in wide composition regions ?and no bulk glass formation was found in the As2Te3-TH sys-tem. As2Te3-based glasses have glass transition tempera-

Study on gold concentrate leaching by iodine-iodide

Gold extraction by iodine-iodide solution is an effective and environment-friendly method. In this study, the method using iodine-iodide for gold leaching is proved feasible through thermodynamic calculation. At the same time, experiments on flotation gold concentrates were carried out and encouraging results were obtained. Through optimizing the technological conditions, the attained high gold leaching rate is more than 85%. The optimum process conditions at 25℃ are shown as follows： the initial iodine concentration is 1.0%, the iodine-to-iodide mole ratio is 1：8, the solution pH value is 7, the liquid-to-solid mass ratio is 4：1, the leaching time is 4 h, the stirring intensity is 200 r/mim, and the hydrogen peroxide consumption is 1%.

Electron Momentum Spectroscopy of Valence Orbitals of n-Propyl Iodide： Spin-Orbit Coupling Effect and Intramolecular Orbital Interaction

The binding energy spectrum and electron momentum distributions for the outer valence orbitals of n-propyl iodide molecule have been measured using the electron momentum spectrometer employing non-coplanar asymmetric geometry at impact energy of 2.5 keV plus binding energy. The ionization bands have been assigned in detail via the high accuracy SACCI general-R method calculation and the experimental momentum profiles are compared with the theoretical ones calculated by Hartree-Fock and B3LYP/aug-cc-pVTZ（C,H）6-311G？？（I）. The spin-orbit coupling effect and intramolecular orbital interaction have been analyzed for the outermost two bands, which are assigned to the iodine 5p lone pairs, using NBO method and non-relativistic as well as relativistic calculations. It is found that both of the interactions will lead to the observed differences in electron momentum distributions. The experimental results agree with the relativistic theoretical momentum profiles, indicating that the spin-orbit coupling effect dominates in n-propyl iodide molecule.