贫PbI_(2)基体的胶体量子点固体用于高效红外太阳能电池

胶体量子点(CQD)具有优异的红外光吸收能力和光谱可调特性,是用于制备高效太阳能电池最有前途的红外光电材料之一。然而,以醋酸铵(AA)为添加剂的液相配体交换会导致CQD固体中产生宽带隙PbI_(2)基质,其将作为电荷传输势垒,在很大程度上影响了CQD太阳能电池(CQDSC)中载流子的提取,从而影响了光伏性能。本文报道利用二甲基碘化铵(DMAI)调节CQD配体交换过程,使载流子在CQD固体中的传输势垒大幅降低。通过对CQD固体进行全面的表征和理论计算,充分揭示了DMAI和CQD之间的相互作用。结果表明,通过DMAI调节CQD配体交换过程,使CQD固体均匀堆积,提高了载流子输运性能,并且陷阱辅助复合受到显著抑制。因此,CQDSC器件中的载流子提取得到了大幅提高,能量转换效率(PCE)比用AA制备的CQDSC器件提高了17.8%。此工作为调控CQD表面化学特性提供了新的研究思路,并为降低CQD固体中载流子输运的势垒提供了可行的方法。

SnO_(2)表面卤化提高钙钛矿太阳能电池光伏性能

钙钛矿太阳能电池(PSCs)成为近几年来迅速发展的新型太阳能电池,其中将SnO_(2)纳米粒子层用作电子传输层(ETL)的钙钛矿太阳能电池器件得到了广泛的关注。SnO_(2)有着更低的制备温度,使其具备应用于柔性器件的潜力,但与钙钛矿层能级不匹配等问题限制着其发展。而在界面处加入钝化层,尤其是表面卤化的方法或可解决这一问题。本文综合研究了SnO_(2)表面卤化对钙钛矿太阳能电池光伏性能的影响,选用四丁基氯化铵(TBAC)、四丁基溴化铵(TBAB)和四丁基碘化铵(TBAI)三种钝化材料对SnO_(2)表面进行钝化处理,并对钝化材料溶液进行了浓度梯度研究。通过材料形貌、结构和光学性能表征以及电池器件性能测试分析等方法,证明了SnO_(2)表面卤化可提高钙钛矿层的质量和PSCs光伏性能,并从器件内部电荷传输动力学等角度解释了器件性能改善的原因。为进一步说明其性能改善的机理,采用基于密度泛函理论(DFT)的第一性原理计算方法对材料表面性质进行了深入研究,从能量、结构、电荷密度、态密度、功函数等角度解释了表面卤化提高SnO_(2)/钙钛矿界面处电子传输特性的原因。实验和理论计算均表明TBAC对于SnO_(2)具有较好的钝化效果,并随着溶液浓度的提升钝化作用越明显。SnO_(2)表面卤化作用的深入研究不仅对提高电池器件性能具有实际意义,还能够帮助理解太阳能电池界面现象,为界面改性提供新的研究思路。

Surface passivation and hole extraction:Bifunctional interfacial engineering toward high-performance all-inorganic CsPbIBr2 perovskite solar cells with efficiency exceeding 12%

All-inorganic CsPbIBr2perovskite solar cells(PSCs)have attracted considerable research attention in recent years due to their excellent thermal stability.However,their power conversion efficiencies(PCEs)are relatively low and still far below the theoretical limit.Here,we report the use of an organic dye molecule(namely VG1-C8)as a bifunctional interlayer between perovskite and the hole-transport layer in CsPbIBr2PSCs.Combined experimental and theoretical calculation results disclose that the multiple Lewis base sites in VG1-C8 can effectively passivate the trap states on the perovskite films.Meanwhile,theπ-conjugated dye molecule significantly accelerates the hole extraction from the perovskite absorber as evidenced by the photoluminescence analysis.Consequently,the VG1-C8 treatment simultaneously boosts the photovoltage and photocurrent density values from 1.26 V and 10.80 mA cm^(-2) to 1.31 V and 12.44 m A cm^(-2),respectively.This leads to a significant enhancement of PCE from 9.20%to12.10%under one sun irradiation(AM 1.5G).To our knowledge,this is the record efficiency reported so far for CsPbIBr_(2) PSCs.Thus,the present work demonstrates an effective interfacial passivation strategy for the development of highly efficient PSCs.

Modulating CsPbl_(3)crystallization by using diammonium agent for efficient solar cells

Cesium lead triiodide(CsPbI_(3))perovskite receives tremendous attention for photovoltaic applications,owing to its remarkable thermal stability and optoelectronic properties.However,realizing the CsPbI_(3)perovskite with high black-phase stability and optoelectronic properties remains a significant challenge,which largely affects the photovoltaic performance of perovskite solar cells(PSCs).Herein,aromatic ammonium agents are used to modulate the crystallization of the CsPbI_(3)perovskite to improve its black-phase stability and optoelectronic properties for efficient PSCs.Systemically experimental studies and comprehensively theoretical calculations are performed,which reveal that histammonium dihydrochloride(HACl_(2))could strongly couple with the perovskite during its crystallization,leading to faster nucleation and slower perovskite growth,and thus modulating the crystallization dynamics of the perovskites.Moreover,the residual diammonium cations(HA^(2+))distributed at the grain boundaries and on the surface of the perovskites can effectively passivate defects through electrostatic interactions,substantially suppressing trap-assisted nonradiative recombination,and prompting more matched perovskite surface energetics.Consequently,the photovoltaic performance of CsPbI_(3)PSCs is largely improved because of a combination of enhanced crystallinity and optoelectronic properties of the perovskites.This work offers a new avenue to prepare inorganic perovskites with high optoelectronic properties for photovoltaics.

Curative effect of Xuebijing injection on severe pulmonary contusion

OBJECTIVE： To investigate the curative effects of Xuebijing （XBJ） injection, a Chinese patent medi- cine, on severe pulmonary contusion （PC）. METHODS： Sixty-three patients with PC were ran- domized to conventional therapy plus XBJ injec- tion （n=33） or conventional therapy alone （n=30）. Between groups differences in corticosteroid treat- ment, immune regulation therapy, hemofiltration, infusion volume, transfusion volume and antibiotic period were measured, as were intensive care unit（ICU）-free time, ventilation time, 28-day mortality rate and incidence of ventilation-associated pneu- monia （VAP）. Serum concentrations of procalcito- nin （PCT）, tumor necrosis factor-a （TNF-a）, interleu- kin （IL）-6, and 11_-10, white blood cell （WBC） counts and percentages of human leukocyte antigen DR/ CD14＋ （HLA-DR/CD14＋） peripheral blood mononu- clear cells were compared. Markers of ventilation were determined by blood gas analysis and ventila- tor parameters. RESULTS： WBC counts and serum concentrations of PCT, TNF-a, 11.-6 and IL-10 were reduced signifi- cantly more quickly, and CD14＋ percentage was in- creased significantly earlier, in the XBJ group than in the control group （P〈0.05 each）. The level of ven- tilation and oxygenation index were ameliorated earlier in the XBJ than in the control group （P〈 0.05）. XBJ treatment significantly reduced ICU-free time, ventilation time and incidence of VAP （P〈0.05 each）, but had no effect on 28-day mortality rate （P〉0.05）. CONCLUSION： XBJ treatment can shorten ICU-free and ventilation times and reduce the incidence of VAP, improving outcomes in patients with severe PC. XBJ may act by regulating inflammation and im- munity, alleviating systemic inflammatory response syndrome induced by trauma.

Ligand exchange engineering of FAPbI_(3) perovskite quantum dots for solar cells

Formamidinium lead triiodide(FAPbI_(3))perovskite quantum dots(PQDs)show great advantages in photovoltaic applications due to their ideal bandgap energy,high stability and solution processability.The anti-solvent used for the post-treatment of FAPbI_(3) PQD solid flms signifcantly afects the surface chemistry of the PQDs,and thus the vacancies caused by surface ligand removal inhibit the optoelectronic properties and stability of PQDs.Here,we study the efects of diferent anti-solvents with diferent polarities on FAPbI_(3) PQDs and select a series of organic molecules for surface passivation of PQDs.The results show that methyl acetate could efectively remove surface ligands from the PQD surface without destroying its crystal structure during the post-treatment.The benzamidine hydrochloride(PhFACl)applied as short ligands of PQDs during the post-treatment could fll the A-site and X-site vacancies of PQDs and thus improve the electronic coupling of PQDs.Finally,the PhFACl-based PQD solar cell(PQDSC)achieves a power conversion efciency of 6.4%,compared to that of 4.63%for the conventional PQDSC.This work provides a reference for insights into the surface passivation of PQDs and the improvement in device performance of PQDSCs.