Bifunctional Ultrathin PCBM Enables Passivated Trap States and Cascaded Energy Level toward Efficient Inverted Perovskite Solar Cells

2020 ◽  
Vol 12 (17) ◽  
pp. 20103-20109 ◽  
Author(s):  
Dongyang Li ◽  
Weiguang Kong ◽  
Haichao Zhang ◽  
Deng Wang ◽  
Wang Li ◽  
...  
Author(s):  
Jing Ren ◽  
Shurong Wang ◽  
Jianxing Xia ◽  
Chengbo Li ◽  
Lisha Xie ◽  
...  

Defects, inevitably produced in the solution-processed halide perovskite films, can act as charge carrier recombination centers to induce severe energy loss in perovskite solar cells (PSCs). Suppressing these trap states...


2020 ◽  
Vol 8 (25) ◽  
pp. 12723-12734 ◽  
Author(s):  
Yang Yang ◽  
Minh Tam Hoang ◽  
Disheng Yao ◽  
Ngoc Duy Pham ◽  
Vincent Tiing Tiong ◽  
...  

Carbon electrode-based planar PSCs demonstrated higher device performance and reduced hysteresis using a CuSCN based HTL owing to its favourable energy level alignment with the perovskite compared to conventional spiro-OMeTAD based HTL.


Science ◽  
2021 ◽  
Vol 371 (6532) ◽  
pp. eabd8598
Author(s):  
Zhenyi Ni ◽  
Shuang Xu ◽  
Jinsong Huang

Ravishankar et al. claimed that drive-level capacitance profiling (DLCP) cannot resolve trap density in perovskites of given thickness. We point out that the trap densities derived by DLCP are from the differential capacitance at different frequencies; thus, the background charges caused by diffusion and geometry capacitance have been subtracted. Even for the nondifferential doping analysis, the contribution from diffusion capacitance is negligible and that from geometry capacitance is excluded.


2020 ◽  
Author(s):  
Yassine Raoui ◽  
Hamid Ez-Zahraouy ◽  
Samrana Kazim ◽  
Shahzada Ahmad

<p>Mixed cation and anion based perovskites solar cells (FAPbI<sub>3</sub>)<sub>0.85</sub>(MAPbBr<sub>3</sub>)<sub>0.15</sub> gave enhanced stability under outdoor conditions, however, it yielded limited power conversion efficiency when SnO<sub>2</sub> and Spiro-OMeTAD were employed as electron and hole transport layer (ETL/HTL). The inevitable interfacial recombination of charge carriers at ETL/perovskite and perovskite/HTL interface diminished the efficiency in planar (n-i-p) perovskite solar cells. Employing computational approach for uni-dimensional device simulator, the effect of band offset on charge recombination at both interfaces were investigated. We noted that it acquired cliff structure when the conduction band minimum of the ETL is lower than that of the perovskite, and thus maximizes interfacial recombination. However, if the conduction band minimum of ETL is higher than perovskite, i.e. spike structure is formed, which improve the performance of solar cell up to an optimum value of conduction band offset allowing to reach performance of 25.21%, with an open circuit voltage (<i>V</i><sub>oc</sub>) of 1231 mV, a current density <i>J</i><sub>sc</sub> of 24.57 mA/cm<sup>2</sup> and a fill factor of 83.28%. Additionally, we found that beyond the optimum offset value, large spike structure could decrease the performance. With an optimized, energy level of Spiro-OMeTAD and the thickness of mixed-perovskite layer performance of 26.56 % can be attained. Our results demonstrate a detailed understanding about the energy level tuning between the charge selective layers and perovskite and furthermore how the improvement in PV performance can be achieved by adjusting the energy level offset.</p>


2018 ◽  
Vol 383 ◽  
pp. 59-71 ◽  
Author(s):  
Md Arafat Mahmud ◽  
Naveen Kumar Elumalai ◽  
Mushfika Baishakhi Upama ◽  
Dian Wang ◽  
Vinicius R. Gonçales ◽  
...  

2018 ◽  
Vol 08 (02) ◽  
pp. 1850009
Author(s):  
Enqi Wang ◽  
Peng Chen ◽  
Xingtian Yin ◽  
Bowen Gao ◽  
Wenxiu Que

It is well known that electron transport layer (ETL) plays an indispensable role in the planar heterojunction perovskite solar cells (PSCs). TiO2 is widely used as an ETL material due to its excellent transport properties, however, the presence of defects in the TiO2 layer diminishes the power conversion efficiency (PCE) of the devices. Herein, we introduce a method of low-temperature TiCl4 treatment to deposit a TiOx layer on the surface of TiO2 film, which can effectively passivate trap states at the TiO2 surface. Moreover, the treating process is optimized to be 30[Formula: see text]min using a 40[Formula: see text]mM TiCl4 aqueous solution. Benefiting from this, we obtain the champion device with the highest PCE of 18.47%, which is mainly due to the reduction of surface defects and the deposition of the well-crystallized perovskite films. Besides, the modified PSCs exhibit an average PCE of 17.59%, which is much better than the control devices.


Author(s):  
Bening Tirta Muhammad ◽  
Teddy Salim ◽  
Annalisa Bruno ◽  
Andrew Clive Grimsdale ◽  
Wei Lin Leong

Titanium dioxide (TiO2) electron transport layers (ETLs) are still widely used in perovskite solar cells (PSCs) due to their compatibility with existing printing technologies and favorable energy level alignment for...


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