钙钛矿太阳能电池的制备工艺与光伏性能研究

设计和制备结构为FTO玻璃/TiO2致密层/TiO2介孔层/CH3NH3PbI3吸收层/C电极的钙钛矿太阳能电池.采用两步法制备CH3NH3PbI3吸收层:首先通过旋涂技术制备PbI2薄膜,然后将PbI2薄膜在浓度为0.044 mol/L的甲基碘化胺/异丙醇(MAI/IPA)溶液中分别浸泡反应0.5 h、2.5 h、3.5 h和4.0 h后获得CH3NH3PbI3吸收层.研究了浸泡反应时间对CH3NH3PbI3吸收层的结构和形貌以及对电池光伏性能的影响.结果表明:PbI2薄膜在MAI/IPA溶液中反应后形成四方结构的CH3NH3PbI3晶粒,当浸泡反应3.5 h时,CH3NH3PbI3晶粒的平均尺寸最大,均匀性较好;XRD图谱中只有CH3NH3PbI3的特征峰,而PbI2的特征峰完全消失.同时,该条件下制备的钙钛矿太阳能电池的光伏性能最佳,其开路电压0.881 V、短路电流密度达到22.17 mA/cm2,光电转化效率6.79;,且在整个可见光区的光子-电子的转换效率接近50;.     

碱金属碘化物后处理制备大晶粒CH3NH3PbI3钙钛矿薄膜,

有机-无机杂化钙钛矿太阳电池作为一种低成本、高效的光伏技术具有巨大的发展潜力,制备大晶粒、致密的钙钛矿吸收层仍然是获得高效钙钛矿太阳电池的关键因素.本文采用简单碱金属碘化物(NaI,KI,CsI)后处理方法诱导CH3NH3PbI3薄膜二次结晶,成功制备了微米级大晶粒、致密的CH3 NH3 PbI3钙钛矿薄膜.与KI相比,NaI和CsI更有利于促进钙钛矿薄膜晶粒长大.并且碱金属碘化物后处理能够钝化晶界,降低钙钛矿薄膜内的缺陷.最后,碱金属掺杂对CH3NH3PbI3带隙的影响很小,不改变其接近单节电池带隙的最优值.因此,碱金属碘化物后处理是进一步提高钙钛矿太阳电池的有效方法.     

退火温度对混合阳离子钙钛矿太阳能电池性能的影响

通过不断降低钙钛矿的带隙,拓宽光活性层的光吸收范围是提高钙钛矿太阳能电池光电转换效率的一个有效途径.本文通过在三碘亚铅酸甲脒(HC(NH2)2PbI3简称FAPbI3)前驱液中混入一定比例的碘化甲铵(CH3NH3I简称MAI)并将其退火温度从150 ℃降低到100 ℃,不仅能有效改善钙钛矿薄膜的表面形貌和结晶度,还能得到比三碘亚铅酸甲铵(CH3NH3PbI3简称MAPbI3)更窄带隙的薄膜,由此得到效率达14.8;钙钛矿太阳能电池器件.     

基于溶剂工程制备高效率钙钛矿太阳能电池

溶剂对钙钛矿(CH3 NH3 PbI3)太阳能电池的制备非常重要,基于目前常用的N,N-二甲基甲酰胺(DMF)和二甲基亚砜(DMSO)两种溶剂,通过一步旋涂技术制备钙钛矿薄膜,在不同溶剂的比例下制备出来的钙钛矿薄膜质量、结晶性、吸光性能,以及最终的器件转化效率都存在着较大的差异.本文通过调节溶剂的比例,研究其对钙钛矿的薄膜的形貌、结晶性、成膜质量等方面的影响.通过优化DMF和DMSO的比例,得到当DMSO:DMF的比例为7:3时,制备出的钙钛矿薄膜质量最高,用该薄膜制备的钙钛矿太阳能电池器件效率高达19.13;,并结合扫描电子显微镜(SEM)、X射线衍射(XRD)、紫外吸收光谱(UV-vis)、稳态荧光光谱(PL)等表征手段,具体分析了合适的溶剂比例提升钙钛矿太阳能电池器件效率.     

CsGeI3空穴传输层平面异质结钙钛矿太阳电池的模拟优化

采用AFORS-HET软件对CsGeI3空穴传输层(Hole Transport Material, HTM)平面异质结钙钛矿太阳电池进行了模拟,TiO2作为电子传输层,CH3NH3PbI3作为光吸收层,C作为背电极,分别讨论了钙钛矿光吸收层厚度、缺陷浓度,光吸收层/HTM界面态密度和HTM对太阳电池性能参数的影响.模拟优化得到CsGeI3 HTM的PSCs最佳性能参数为:Voc=1.199 V,Jsc=22.2 mA·cm-2,FF=86.22;,PCE=22.95;,效率虽略低于spiro作为HTM的器件,但考虑生产工艺和制备成本,CsGeI3作为HTM的PSCs将具有更好的应用前景.     

电沉积法制备Bi2S3薄膜研究

采用阴极恒电压法在ITO导电玻璃表面沉积了Bi2S3薄膜,利用X射线衍射(XRD)、原子力显微镜(AFM)对制备的薄膜进行了表征.研究了pH值、沉积时间、沉积液浓度等工艺因素对薄膜的影响.结果表明:电沉积制备Bi2S3薄膜的过程中,合适的Bi3+与S2O32-的浓度水平是至关重要的;在电沉积溶液pH=6.5,沉积时间为20 min,沉积电压为1 V,加入柠檬酸三钠作络合剂的情况下,得到沿(240)晶面生长良好的Bi2S3薄膜,薄膜组成均匀致密;增加沉积溶液pH值,薄膜的结晶程度逐渐提高,红外透过比提高.     

以B-γ-CsSnI3为光吸收层的平面异质结钙钛矿太阳能电池的模拟优化

采用AFORS-HET软件对以B-γ-CsSnI3作为光吸收层的平面异质结钙钛矿太阳能电池结构进行了模拟优化,其中TiO2作为电子传输层,Spiro-OMeTAD作为空穴传输层,讨论了钙钛矿太阳能电池光吸收层以及空穴传输层的各种参数对太阳能电池性能的影响.模拟优化得到B-γ-CsSnI3的PSCs最佳性能参数为:Voc=1.18 V,Jsc=24.48 mA/cm2,FF=80.04;,PCE=23.15;,效率虽略低于以CH3NH3PbI3作为光吸收层的钙钛矿太阳能电池,但考虑铅的毒性和钙钛矿电池的稳定性,以B-γ-CsSnI3作为光吸收层的PSCs将具有更好的应用前景.     

基于咔唑的新型空穴传输材料及其在PSC中的应用

为了开发新型的太阳能电池关键材料,合成了一种新的基于咔唑的小分子材料Cz-3Th,将其用作空穴传输材料(HTM)成功地应用到钙钛矿太阳能电池当中.这种新型的小分子材料两步反应即可合成,原料易得且成本较低.在使用低温溶液处理的SnO2纳米颗粒作为电子传输层的CH3NH3PbI3钙钛矿太阳能电池中,以Cz-3Th为空穴传输层,在100 mW/cm2 AM 1.5 G光照条件下获得0.75 V的开路电压(Voc),光电转化效率(PCE)为2.68;.因此,在未来趋势为环境友好和低成本效益的钙钛矿太阳能电池中Cz-3Th有很大发展潜力.     

Ag@CH3NH3PbI3等离激元效应增强钙钛矿太阳能电池性能的数值研究

由于银纳米粒子结构的表面等离激元共振特性对有机无机卤化物钙钛矿的新型太阳能电池性能有一定影响,利用comsol mutiphysics多物理场仿真软件对Ag@CH3 NH3 PbI3纳米粒子等离激元效应增强钙钛矿太阳能薄膜电池性能进行研究,对粒子半径和粒子间距对于能量的影响进行了计算;对光敏层能量增强的机理进行了解释;并对电场分布进行了详细说明.依据实验数据,给出优化后的银纳米粒子阵列和钙钛矿光敏层的厚度以及强度,为实验制备高效稳定的钙钛矿太阳能电池提供理论指导.     

MPCVD掺硼金刚石薄膜的制备及Ti/BDD 电极上对硝基酚的阳极氧化测试

采用微波等离子体技术在CH4-H2-C2H6气体条件下制备了钛基掺硼金刚石薄膜.四点探针法测得薄膜电阻率在零掺杂时为1×1012Ω*cm ,当反应气源中B/C上升为5×10-3时电阻率降至5×10-3 Ω*cm.扫描电镜显示掺硼金刚石具有完整晶型和致密结构.拉曼光谱观察到金刚石结构在掺杂前后发生明显改变.采用循环伏安测试了Ti/BDD电极的电化学参量,并与PbO2, Sn-Sb and PbO2-Er三种电极进行阳极氧化对-硝基酚的对比实验.结果表明,在Ti/BDD电极上,对-硝基酚的总有机碳去除率接近100;,远高于其它三种电极.     

Infrared vibrational Modes in Tl3SbS3, Tl3AsS3, and Tl3AsSe3 crystals

Reflectivity spectra of Tl₃SbS₃, Tl₃AsS₃, and Tl₃AsSe₃ crystals have been investigated in the wave number range 50–600 cm⁻¹ for the polarizations E∥c and E⟂c. The fundamental phonon parameters, the limiting dielectric constants ϵ_∞ and ϵ_S and the reflectivity spectra contours have been calculated by using classical dispersion relations for both E∥c and E⟂c configurations. The Szigeti effective charges and the relative ion charges of As, Tl, Sb, Se, S anions and cations have been calculated in dependence on the incident light polarization.     

The structures of three trimethylarsine-boron trihalide adducts: (CH3)3AsBCl3, (CH3)3AsBBr3, and (CH3)3AsBI3

An X-ray structure analysis of three trimethylarsine-boron trihalide adducts has been undertaken. Crystals of (CH₃)₃AsBCl₃ and (CH₃)₃AsBBr₃ are monoclinic with space groupP2₁/m (No. 11) withZ=2 while those of (CH₃)₃AsBI₃ are orthorhombic with space groupPnma (No. 62) withZ=4. For (CH₃)₃AsBCl₃,a=6.497(3) Å,b=10.735(3) Å,c=7.070(2) Å,=111.8(3)°,V=458.4(3) ų,R=0.0343. For (CH₃)₃AsBBr₃,a=6.672(4) Å,b=11.135(7) Å,c=7.199(4) Å,=111.5(1)°,V=497.7(5) ų,R=0.0434. For (CH₃)₃ÅsBI₃,a=13.113(7) Å,b=11.733(5) Å,c=7.387(3) Å,V=1136.5(5) ų,R=0.0329. The As-B bond lengths are 2.065(6), 2.04(1), and 2.03(1) Å, respectively, for the chloride, bromide, and iodide. These and other structural parameters are discussed with reference to previous predictions based on vibrational spectra and previous structural studies on the trimethyl-phosphine and trimethylamine adducts.     

Crystal and molecular structures of three trimethylamine-boron halide adducts: (CH3)3NBCl3, (CH3)3NBBr3, and (CH3)3NBI3

X-ray diffraction data from single crystals of the trimethylamine complexes of the three boron halides, BCl₃, BBr₃, and BI₃, lead to aP2₁/m monoclinic cell containing two molecules for each complex. The unit cell dimensions area = 6·68(1),b = 10·247(3),c = 6·502(6) Å, =116·2(1)° (chloro);a = 6·86(1),b = 10·612(4),c = 6·737(6) Å, = 115·8(1)° (bromo);a = 6·92(2),b = 10·86(1),c = 7·147(6) Å, = 93·9(1)° (iodo). The structures were solved by three-dimensional sharpened Patterson functions and show only the chloro and bromo compounds to be isomorphous. Refinement of 662,718 and 954 observed reflexions for the chloro, bromo and iodo complexes, respectively, using anisotropic thermal parameters yielded conventionalR factors of 0·045, 0·087 and 0·054.The molecules are shown to possess a B—N dative bond, a staggered conformation, and effective 3m (C _3v) symmetry. Average C—N bond lengths are 1·52(1) Å for all three complexes. Boronhalogen bond lengths average 1·864(4), 2·04(2) and 2·28(2) Å, while B—N bond distances are 1·609(6), 1·60(2) and 1·58(3) Å, respectively, for the chloro through iodo compounds. Bond angles are approximately tetrahedral with the C—N—C angle decreasing by several degrees in the Cl Br I series.Based in part on a dissertation submitted by Patty H. Clippard to the Rackham School of Graduate Studies of the University of Michigan, January 1969 in partial fulfillment of the requirements of the Ph.D. Degree.     

Second harmonic generation properties of Ca3(O3C3N3)2 ‐Sr3(O3C3N3)2 solid solutions

Solid solutions of the second harmonic generation (SHG) materials Ca₃(O₃C₃N₃)₂ (CCY) and Sr₃(O₃C₃N₃)₂ (SCY) were prepared via exothermic solid state metathesis reactions from appropriate amounts of the corresponding metal chlorides and potassium cyanate at 525 °C. The change in SHG intensity caused by the successive cation substitution is reported. Differential thermal analyses are used to explore the SCY–K(OCN) phase diagram as a medium for the growth of SCY crystals.     

Crystal Growth and Spectroscopic Characterisation of BiB3O6:RE3+ (RE3+ = Pr3+, Nd3+, Gd3+, Er3+, Tm3+)

Large single crystals of optical quality of BiB₃O₆:RE³⁺ (RE³⁺ = Pr³⁺, Nd³⁺, Gd³⁺, Er³⁺, Tm³⁺) were grown from nearly stoichiometric melts using the top‐seeding growth technique to dimensions up to 12 x 12 x 18 mm³. Absorption spectra were measured in the wavelength range from 10000 cm^‐1 to 30000 cm^‐1 with an absorption spectrometer to estimate the doping concentration of RE³⁺. For the determination of the phonon energies and the quenching behaviour of the host lattice IR and Raman spectra were recorded.     

Growth and characteristic of Sr3Tb(BO3)3 crystal

A new borate single crystal of Sr₃Tb(BO₃)₃ with dimension Ф20×25 mm² has been grown by the Czochralski method. The grown crystal was characterized by DTA–TGA, FTIR and X-ray powder diffraction analysis. The results showed the crystal with [BO₃]^3? is congruently melting at 1351.35 °C which belongs to hexagonal structure. The hardness of Sr₃Tb(BO₃)₃ crystal is 422.5 VDH, and is equal to 5.0 moh. The thermal expansion coefficients were determined to be 2.08×10^?5/°C along (1 0 0) direction and 7.43×10^?6/°C along (0 0 1) direction and the transmission spectrum was measured in 320–1800 nm at room temperature. The magnetic properties of the single crystal were studied which showed its paramagnetism and magnetic anisotropy. The specific Faraday rotation of single crystal was measured at room temperature in 532, 633, and 1064 nm wavelength. The Verdet constants and magneto-optical figures of merit were investigated. The primary emphasis is laid to explore a new magneto-optical material, all the magneto-optical properties of Sr₃Tb(BO₃)₃ are comparing to the ones of TGG.     

Tb3+,Yb3+共掺杂LuBO3荧光粉的下转换发光

利用水热法成功合成了近红外量子剪裁荧光粉LuBO3∶15;Tb3+,x; Yb3+(x=0,1,2,4,8,12).通过X射线衍射(XRD)、光致发光谱(PL)、激发谱(PLE)和荧光寿命测试了合成物质的物相结构与发光性质.在286 nm(Tb3+∶7 F6→5D)紫外光激发下,观察到了Tb3∶5D4→7Fj(J=6,5,4,3)可见波段特征发射光和Yb3+:2F5/2→2F7/2的近红外光.研究了Yb3+浓度与激发发射光谱和荧光寿命之间的关系,表明Tb3+和Yb3+之间存在能量传递.当Tb3和Yb3+掺杂摩尔浓度分别为15;和2;时,近红外发射最强.计算得知,其最大下转换量子效率为160.74;.     

Growth and magnetic‐optical properties of Sr3Gd(BO3)3 and Sr3TbxGd1‐x(BO3)3 single crystals

Single crystals of Sr₃Gd(BO₃)₃ (SGB) and Sr₃Tb_xGd_1‐x(BO₃)₃ (TSGB) with dimension Ø 20 mm×20 mm have been grown by Czochralski method. The grown crystals were characterized by X‐ray powder diffraction analysis which showed the crystals belong to hexagonal structure with lattice parameters of a=b=1.254 nm, c=0.926 nm (SGB) and a=b=1.253 nm, c=0.925 nm (TSGB). In TSGB, x=17.7% was obtained by X‐ray fluorometry which showed the segregation coefficient of Tb is closed to 1. The transmission spectrum was measured, which indicated the crystals have high transmittance in 400‐1100 nm region. The Faraday rotation of single crystals at 532 nm wavelength was measured at room temperature. Finally, the Verdet constants were investigated, (SGB) V=17.9 degcm^‐1T^‐1 and (TSGB) V=21.3 degcm^‐1T^‐1. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Photoacoustic Spectra of Pr3+, Nd3+, Gd3+ Acetate Complexes

The crystals of the complexes Pr(Ac)₃ · 4 H₂O, Nd(Ac)₃ · 4 H₂O, Gd(Ac)₃ · 4 H₂O were synthesized and their Pa spectra determined firstly. Their PA spectra and absorption are interpreted. The fluorescence properties of Pr³⁺, Nd³⁺, Gd³⁺ and the relaxation process models were studied by their PA spectra.