Molecular exchange and passivation at interface afford high-performing perovskite solar cells with efficiency over 24%

The interface is crucial for perovskite solar cells(PSCs).However,voids at interfaces induced by the trapped hygroscopic dimethyl sulfoxide(DMSO)can reduce charge extraction and accelerate the film degradation,seriously damaging the efficiency and stability.In this work,4,4’-dinonyl-2,2’-dipyridine(DN-DP),a Lewis base with long alkyl chains is introduced to solve this problem.Theoretical calculated and experimental results confirm that the dipyridyl group on DN-DP can more strongly coordinate with Pb^(2+)than that of the S=O group on DMSO.The strong coordination effect plays a crucial role in removing the DMSO-based adduct and reducing the formation of voids.Due to the electron-donating properties of pyridine,the existence of DN-DP in the perovskite film can passivate the defects and optimize the energy level alignment of the perovskite configuration.The open-circuit voltage(VOC)of the DN-DP-based PSC is improved from 1.107 V(control device)to 1.153 V,giving rise to a power conversion efficiency(PCE)of24.02%.Furthermore,benefiting from the moisture resistance stemming from the hydrophobic nonyl group,the PCE retains 90.4%of the initial performance after 1000 h of storage in the ambient condition.

Improving the performance of arylamine-based hole transporting materials in perovskite solar cells： Extending π-conjugation length or increasing the number of side groups？

In this work, we prepared three simple arylamine-based hole transporting materials from commercially available starting materials. The effect of extending 7 r-conjugation length or increasing the number of side groups compared with reference compound on the photophysical, electrochemical, hole mobility properties and performance in perovskite solar cells were further studied. It is noted that these two kinds of molecular modifications can significantly lower the HOMO level and improve the hole mobility, thus improving the hole injection from valence band of perovskite. On the other hand, the compound with more side groups showed higher hole injection efficiency due to lower HOMO level and higher hole mobility compared with the compound with extending π-conjugation length. The perovskite solar cells with the modified molecules as hole transporting materials showed a higher efficiency of 15.40% and 16.95%,respectively, which is better than that of the reference compound(13.18%). Moreover, the compound with increasing number of side groups based devices showed comparable photovoltaic performance with that of conventional spiro-OMeTAD(16.87%).

Localized Electrons Accelerated Ionic and Charge Transfer for Superior Lithium Storage

The electrochemical energy storage performance is greatly determined by the charge transfer and ion transportation occurring in the electrode materials.Therefore,the enhancement of electric conductivity and ionic mobility is vital for high-performing and stable metal ion batteries.Here,we report the properties of oxygen vacancies(VO)and carbon co-doped TiO_(2) hollow spheres(HS-TiO_(2))and compared them with fully oxidized white TiO_(2) hollow spheres(W-TiO_(2)).Theoretical calculations and experimental results revealed that the introduction of carbon dopant and VO in anatase TiO_(2) reduced the bandgap and the existence of localized electrons,leading to a lower migration barrier of Li ions that promoted faster ion diffusion kinetics,enabling the HS-TiO_(2) with higher reversibility during the insertion and extraction of Li ions than the W-TiO_(2).This HS-TiO_(2) delivered superior lithium storage properties with a specific discharge capacity of 214.6 mAh g^(-1) for the 100th cycle at 200 mA g^(-1) and 116.3 mAh g^(-1) over 2000 cycles at a high rate of 2 A g^(-1).

Inside-out Ostwald ripening： A facile process towards synthesizing anatase TiO2 microspheres for high- efficiency dye-sensitized solar cells

一灵巧在内外面，到 TiO 2 microspheres 的控制形态学的准备的 Ostwald 成熟线路被开发。这里， TiO 2 空 microspheres (HM ) 和稳固的 microspheres (SM ) 被在 solvothermal 过程以 acetylacetone (Acac ) 调整 isopropanol (国际语音学协会) 的体积比率准备。在 HM，稳固的核心的降水，核心的表面上的外部壳的随后的免职，和同时的核心的形成过程期间，溶解和壳再结晶被观察，它验证在内外面 Ostwald 成熟机制。TiO 2 microspheres 的性质(毛孔尺寸，表面区域，和陷井状态) 的设计和优化对 dyesensitized 太阳能电池(DSSC ) 的高效重要。优化 TiO 2 microspheres (rHM 和 rSM ) 在再结晶上由 processing 以后获得了，拥有大毛孔尺寸，高表面区域和减少的陷井状态(Ti 3+ 和氧空缺) ，并且因此是为光电的设备的理想的材料。用 rHM photoanode 制作的 DSSC 的力量变换效率是 11.22% ，它显著地与基于 rSM 的 DSSC 的 10.54% 效率相比被改进。我们的工作为综合提供策略 TiO 2 microspheres 同时提供不同物理性质以表面区域， crystallinity，形态学，和 mesoporosity。

The pyrolysis preparation of the compact and full-coverage AgSbS_(2) thin films and the photovoltaic performance of the corresponding solar cells

The preparation of the compact and full-coverage AgSbS;thin films is firstly reported using the pyrolysis of the Ag-butyldithiocarbamate and Sb-butyldithiocarbamate complex solution in DMF.The influence of the preparation temperature on the crystal phase,optical absorption,morphology of the AgSbS;thin films is systematically investigated.The AgSbS;thin films at 150°C for 30 min are composed of the individual nanoparticles with the particle sizes of 30–60 nm.When the AgSbS_(2)thin films are further heated at 350℃for 2 min,the individual AgSbS_(2)nanoparticles are melted together and the grain boundary between the AgSbS_(2)nanoparticles disappear.The solar cells with the architecture of FTO/compact TiO_(2)/AgSbS_(2)/spiro-OMe TAD/Au achieve the photoelectric conversion efficiency(PCE)of 2.09%,along with the open-circuit voltage of 0.44 V,the short-circuit photocurrent density of 10.49 m A cm^(-2),the fill factor of 0.45.The PCE of 2.09%is the highest value for the AgSbS_(2)solar cells.