氨甲环酸对于CsPbI2Br钙钛矿太阳能电池性能优化

研究不同摩尔分数氨甲环酸的CsPbI_(2)Br钙钛矿前驱液旋涂退火制得的钙钛矿吸光层薄膜对钙钛矿电池器件性能影响。在实验中检测出当前驱液中氨甲环酸摩尔分数达到0.5%时,钙钛矿吸光层薄膜的微观形貌,薄膜结晶性及光生载流子迁移率均得到明显改善,CsPbI_(2)Br基钙钛矿电池器件光电转化效率为12.14%达到最佳。因此,CsPbI_(2)Br钙钛矿太阳能电池中加入适量的氨甲环酸是一种优化吸光层薄膜,提高钙钛矿太阳能电池性能的可靠途经。

Effective Surface Treatment for High‑Performance Inverted CsPbI2Br Perovskite Solar Cells with Efficiency of 15.92%

Developing high-efficiency and stable inverted CsPbI2Br perovskite solar cells is vitally urgent for their unique advantages of removing adverse dopants and compatible process with tandem cells in comparison with the regular.However,relatively low opening circuit voltage(Voc)and limited moisture stability have lagged their progress far from the regular.Here,we propose an effective surface treatment strategy with high-temperature FABr treatment to address these issues.The induced ions exchange can not only adjust energy level,but also gift effective passivation.Meanwhile,the gradient distribution of FA+can accelerate the carriers transport to further suppress bulk recombination.Besides,the Br-rich surface and FA+substitution can isolate moisture erosions.As a result,the optimized devices show champion efficiency of 15.92%with Voc of 1.223 V.In addition,the tolerance of humidity and operation get significant promotion:maintaining 91.7%efficiency after aged at RH 20%ambient condition for 1300 h and 81.8%via maximum power point tracking at 45°C for 500 h in N2.Furthermore,the unpackaged devices realize the rare reported air operational stability and,respectively,remain almost efficiency(98.9%)after operated under RH 35%for 600 min and 91.2%under RH 50%for 300 min.

Improved open-circuit voltage and ambient stability of CsPbI2Br perovskite solar cells by incorporating CH3NH3Cl

Inorganic cesium metal halide perovskites have gained research interest as absorbers in perovskite solar cells due to their superior thermal stability.Among these,CsPbI2Br,with a narrower band gap than CsPbBr3 and a better phase stability than CsPbI3,has received tremendous interest of the researchers.However,CsPbI2 Br takes adverse phase transfer easily with an exposure to the water vapor in ambient air which not only brings inconvenience for researches but also puts forward very high requirement for encapsulation.Herein,a dense and uniform film is obtained by incorporating hydrophobic CH3NH3Cl(MACl)into the precursor solution.Being attributed to a good passivation effect,the defect density is decreased from3.12×1016 to 1.49×1016 cm-3 and the average photoluminescence lifetime is increased from 8.84 to 20.6 ns.The photovoltaic device achieves a high open-circuit voltage of 1.22 V based on optimized MACl-doped film and accordingly a higher power conversion efficiency(PCE) of 12.9% which is 21.7% higher than the pristine CsPbI2Br device with PCE of 10.6%.In addition,the ambient stability of MACl-doped device has been enhanced,which is greatly attributed to the hydrophobic properties of MACl.This work provides a clue to improve ambient stability of inorganic perovskite solar cells and inspires toward further development of this material.

Defect passivation of CsPbI2Br perovskites through Zn（Ⅱ） doping:toward efficient and stable solar cells

Defect passivation is an important strategy to achieve perovskite solar cells(PVSCs) with enhanced power conversion efficiencies(PCEs) and improved stability because the trap states induced by defects in the interfaces and grain boundaries of perovskites are harmful to both large open circuit voltage and high photocurrent of devices. Here, zinc cations(Zn^2+) were used as a dopant to passivate defects of the CsPbI2Br perovskite leading to Zn^2+-doped CsPbI2Br film with fewer trap states, improved charge transportation, and enhanced light-harvesting ability. Thus, the best-performance PVSC based on CsPbI2 Br with the optimal Zn^2+doping shows a higher PCE of 12.16% with a larger open-circuit voltage(VOC) of 1.236 V, an improved shortcircuit current(JSC) of 15.61 mA cm^-2 in comparison with the control device based on the pure CsPbI2Br which exhibits a PCE of 10.21% with a VOCof 1.123 V, a JSCof 13.27 mA cm^-2. Time-resolved photoluminescence results show that the Zn^2+doping leads to perovskite film with extended photoluminescence lifetime which means a longer diffusion length and subsequently enhanced photocurrent and open circuit voltage. This work provides a simple strategy to boost the performance of PVSCs through Zn^2+doping.

Defect passivation strategy for inorganic CsPbI2Br perovskite solar cell with a high-efficiency of 16.77%

All-inorganic halide perovskite solar cells(PSCs)have acquired great progress,especially CsPbI2Br.However,their photoelectric conversion efficiency(PCE)remains far below the theoretical predictions.Non-radiative recombination is one of the important issues affecting the photoelectric performance of the PSCs,and the defective lead ions derived from the evaporation of halide ions in the inorganic perovskite are the principal non-radiative recombination centers.Herein,the non-radiative recombination is effectively suppressed by introducing the N-methyl-2-pyrrolidone(NMP)as a Lewis base molecule to passivate the defective lead ions.Therefore,by adjusting the dosage of NMP,the smooth and pinhole-free CsPbI_(2)Br perovskite film is obtained and the optimized device exhibits a champion PCE of 16.77%with an excellent fill factor(FF)of 0.80.This work proves the effectiveness of passivation using Lewis base molecules to prevent non-radiative recombination defects in inorganic perovskite.

CsPbI2Br无机钙钛矿太阳能电池稳定性的研究进展

有机-无机杂化钙钛矿材料中易挥发的有机成分(MA+,FA+)用高耐热性无机金属铯离子(Cs+)取代,用其制备的太阳能电池具有优异的热稳定性。自2016年以来,以CsPbI2Br材料作为光活性层的无机钙钛矿太阳能电池(IPSCs)的光电转换效率(PCE)从9.84%提高到18.06%,但是IPSCs的稳定性问题仍然制约其商业化。本文总结和分析了影响CsPbI2Br IPSCs稳定性的因素,从制备工艺、离子掺杂、界面优化等方面评述了近年来IPSCs稳定性的研究进展,并展望了CsPbI2BrIPSCs的研究趋势和发展方向。

Improved phase stability of CsPbI2Br perovskite by released microstrain toward highly efficient and stable solar cells

All-inorganic perovskite solar cells(PSCs)have developed rapidly in the field of photovoltaics due to their excellent thermal and light stability.However,compared with organic–inorganic hybrid perovskites,the phase instability of inorganic perovskite under humidity still remains as a critical issue that ham-pers the commercialization of inorganic PSCs.We originally propose in this work that microstrains between the perovskite lattices/grains play a key role in affecting the phase stability of inorganic perovskite.To this end,we inno-vatively design theπ-conjugated p-type molecule bis(2-ethylhexyl)3,30((4,8-bis(5-(2-ethylhexyl)-3,4-difluorothiophen-2-yl)benzo[1,2-b:4,5-b0]dithiophene-2,6-di yl)bis(3,300-dioctyl[2,20:50,200-terthiophene]-500,5-diyl))(2E,20 E)-bis(2-cyanoacrylate)(BTEC-2F)to covalent with the Pb dangling bonds in CsPbI2Br perovskite film,which significantly suppress the trap states and release the defect-induced local stress between perovskite grains.The interplay between the microstrains and phase stability of the inorganic perovskite are scrutinized by a series of charac-terizations including x-ray photoelectron spectroscopy,photoluminescence,x-ray diffraction,scanning electron microscopy,and so forth,based on which,we conclude that weaker local stresses in the perovskite film engender superior phase stability by preventing the perovskite lattice distortion under humidity.By this rational design,PSCs based on CsPbI2Br perovskite system deliver an outstanding power conversion efficiency(PCE)up to 16.25%.The unencapsulated device also exhibits an exceptional moisture stability by retaining over 80%of the initial PCE after 500 h aging in ambient with relative humidity of(RH)25%.

Simultaneously enhanced efficiency and ambient stability of inorganic perovskite solar cells by employing tetramethylammonium chloride additive in CsPbI2Br

Although all-inorganic perovskites possess suitable bandgap and thermal stability for photovoltaic ap-plications,the unstable film morphologies,and poor moisture stabilities lag behind the organic-inorganic hybrid counterparts.Herein,we demonstrate that high qualityα-CsPbI_(2 ) Br films with improved phase sta-bility,high crystallinity,and pinhole-free film morphology was achieved by employing tetramethylammo-nium chloride(TMACl)as an additive.As a result,the TMACl-added CsPbI_(2) Br films exhibited high power conversion efficiency of 14.12%with an open-circuit voltage of 1.19 V,a short-circuit current density of 15.08 mA/cm^(2),and a fill factor of 0.78.More importantly,the TMACl addition imparts hydrophobicity to the film surface of CsPbI_(2) Br,which delivered excellent stability up to 30 days in the ambient condition and thermal stability at 85℃ for 156 h,respectively.Moreover,the TMACl-added device also exhibited excellent PCE of 27.16%under indoor light source(1000 lux),which presents a promising approach for designing stable but high performance all-inorganic perovskite solar cells.

由p型CuI颗粒覆盖层诱发的全无机CsPbI2Br钙钛矿薄膜的相变研究

由于具有良好的光吸收特性和光热稳定性,富碘型全无机钙钛矿结构CsPbI2Br光电功能材料受到了广泛关注.然而,具有钙钛矿结构的α相CsPbI2Br在高湿度环境下易发生相变,转变为具有非钙钛矿结构的δ相CsPbI2Br.因此基于CsPbI2Br材料的光电器件通常需要在干燥环境中保存以维持器件性能稳定.在本研究中,我们将干燥且不吸湿的p型无机空穴传输材料Cu I的颗粒涂覆在α相CsPbI2Br薄膜表面并对样品进行加热,实验测试结果表明,这层CuI颗粒同样会诱发α相CsPbI2Br转变为δ相CsPbI2Br,且该相变过程的速率随加热温度的升高、CuI颗粒覆盖度的提升而加快.这种异于湿度诱导的钙钛矿结构CsPbI2Br相变行为,为研究者在思考、评估和分析基于富碘型全无机钙钛矿结构CsPbX3(X=Br,I)光电功能材料的高性能光电器件稳定性问题上,提供了有益的借鉴和帮助.

退火温度对碳基全无机钙钛矿太阳能电池性能的影响

碳基全无机钙钛矿太阳能电池(carbon-basedall-inorganicperovskitesolar cells,C-PSCs)由于成本低、热稳定性好等优点逐渐引起人们的广泛关注,然而其效率要远低于传统的钙钛矿太阳能电池(perovskite solar cells,PSCs)。通过调控CsPbI_(2)Br薄膜的退火温度,改善薄膜质量。利用SEM、XRD表征分析了钙钛矿薄膜微观形貌以及物相结构,发现升高退火温度可有效提高CsPbI_(2)Br薄膜的结晶性从而减少其表面的孔洞。升高钙钛矿薄膜的退火温度,器件的光伏性能有显著提高,短路电流密度(J_(sc))从8.84 mA·cm^(-2)提高至12.14 mA·cm^(-2),开路电压(V_(oc))从0.93 V提高至1.06 V,最终能量转换效率(PCE)从2.75%提高至7.63%。研究结果表明,优化钙钛矿太阳能电池的制备工艺可以有效提高其光伏性能。