混摻“前趨物表面修飾的奈米粒子”促進鈣鈦礦太陽能電池薄膜的成長及其光電轉換效率

Intermixing-seeded Growth for High-performance Planar Heterojunction Perovskite Solar Cells Assisted by Precursor-capped Nanoparticles

李紹先(Shao-Sian Li) ； 蕭妤芸(Yu-Yun Hsiao) ； 張啟皇(Chi-Huang Chang) ； 王映樵(Ying-Chiao Wang) ； 林忠緯(Chung-Wei Lin) ； 陳家俊(Chia-Chun Chen) ； 賈浩中(Hao-Chung Chia) ； 許火順(Hwo-Shuenn Sheu) ； 吳瑋儒(Wei-Ru Wu) ； 鄭有舜(U-Ser Jeng) ； 陳俊維(Chun-Wei Chen)

《化學》 75卷2期 (2017/06) Pp. 179-186

https://doi.org/10.6623/chem.2017015

摘要

在本研究中，我們提出了一種新穎且適合溶液法製程的技術，用來改善一般鈣鈦礦CH_3NH_3PbI_(3-x)Cl_x太陽能電池的薄膜品質及光電轉換效率。此種新技術利用表面修飾工程，在無機奈米粒子硫化鉛表面接覆鈣鈦礦材料的前趨物(CH_3NH_3I)，並加入一般鈣鈦礦材料的前趨物溶液中，使之扮演類似成核點的晶種，用以改善及控制CH_3NH_3PbI_(3-x)Cl_x的成核成長機制，增進薄膜結晶性質與表面覆蓋率。使用此新製程技術的太陽能電池之光電轉換效率可到17.4%，與一般元件相比，大約提升了25%的效率。藉由同步幅射2D GIWAXS及時間解析螢光光譜的量測，光電轉換效率的增益可歸因於垂直向結晶性質的改善，造成更長的載子擴散長度及更有效率的載子傳輸能力。

關鍵字

鈣鈦礦太陽能電池 ； 硫化鉛奈米粒子 ； 混摻異質成核 ； GIWAXS ； 載子傳輸

並列摘要

This work proposes a novel approach to modulate the nucleation and growth of perovskite crystals in planar perovskite (CH_3NH_3PbI_(3-x)Cl_x) solar cells by intermixing precursor-capped inorganic nanoparticles of PbS. A small amount of dispersed PbS nanoparticles which were covered with perovskite precursor molecules of methylammonium iodide (CH_3NH_3I) through the ligand-exchange treatment functioned as effective seed-like nucleation sites to promote the formation of perovskite lattice structures. Through this intermixing-seeded growth technique, substantial morphological improvements, such as increased crystal domains, enhanced coverage, and uniformity, were realized in the perovskite thin films, and the corresponding solar cell devices exhibited a promising power conversion efficiency of 17.4%, showing an enhancement of approximately 25% compared to that of the controlled pristine solar cell device. The substantially enhanced crystal orientation, particularly along the direction perpendicular to the substrate, was evident from the synchrotron-based grazing incidence wide-angle X-ray scattering data. This observation was consistent with the enhanced carrier diffusion lengths and excellent reproducibility of high fill factors of the planar heterojunction perovskite devices fabricated through the proposed technique.

並列關鍵字

Perovskite solar cell ； PbS nanoparticle ； Intermixing seeded growth ； GIWAXS ； Carrier transport