奈秒脈衝雷射雕刻技術應用於可撓性鈣鈦礦太陽能電池模組的製造

Laser Patterning Technology Based on Nanosecond Pulsed Laser for Fabricating Flexible Perovskite Solar Modules

黃章栢(Zhang-Bo Huang)

指導教授 ： 許麗

國立臺灣大學/工學院/機械工程學系/碩士(2023年)

https://doi.org/10.6342/NTU202300227

摘要

置身於第三代太陽能電池領域技術發展中，鈣鈦礦太陽能電池已成為重要發展趨勢，在玻璃基板上於2009年首次製作出光電轉換效率3.8%的鈣鈦礦太陽能電池後，便在數十年間光電轉換效率即可達到25.7%，而鈣鈦礦太陽能電池的一大特性就是可以使用低溫製程，這使得可以製造於可撓性基板上，目前已達到22.4%的光電轉換效率。然而，這些高效率的元件都為小面積(＜0.1 cm2)，在朝往商業化模組開發的路上仍然有許多技術困難須克服，其中雷射雕刻的單片整合技術是關鍵環節之一。本實驗著重於研究在可撓性基板上，並通過旋塗法鍍膜，以雷射雕刻技術完成可撓性鈣鈦礦太陽能電池模組的製作。鈣鈦礦電池模組製作則是將電池以單片串聯模組的方式，藉由三條雷射切割線P1、P2和P3讓多顆電池互相串連。P1切割下電極用於定義單個子電池大小，P2讓上下電極能相互導通，最後P3切割上電極，重複此步驟完成電池串聯。我們使用波長為532 nm的奈秒脈衝雷射，在大氣環境下進行雷射雕刻，透過調整脈衝重疊率和雷射能量密度進行參數優化，探討P1切割線對後續鈣鈦礦電池鍍膜均勻性的影響，P2切割線所使用之雷射參數對接觸電阻的影響，以及P3切割線於上電極的效果。在提升鈣鈦礦電池的效率方面透過改變電洞傳輸層的方式，加入修飾層使得電壓與電流皆提升，在0.09 cm2的發電面積下讓玻璃與可撓性基板的鈣鈦礦電池效率從12.7%和7.9%提升至14.4%與10.8%，以此標準作為後續模組化製程的基礎。
最後，在2×2 cm2的玻璃基板與可撓性基板上，利用旋塗法的方式並串聯兩顆子電池形成模組，可做出有效發電面積1.0 cm2其光電轉換效率分別12.5%與10.1%的模組，填充因子都達到69.1%與60.1%，相比小面積的標準片只降低12%和6%，代表本實驗有效地以全雷射切割的方式完成模組，可應用於未來大面積塗佈法下使用相同雷射切割參數實現卷對卷或片對片的製程。

關鍵字

可撓性鈣鈦礦太陽能電池 ； 全雷射雕刻模組 ； 奈秒脈衝雷射

並列摘要

In the development of the third generation of solar cells, perovskite (PVSK) solar cells have become an important trend in research development. Since the first perovskite solar cell (PSC) was reported on the glass substrate in 2009, with a power conversion efficiency (PCE) of 3.81%, the power conversion efficiency (PCE) of perovskite solar cell (PSC) has increased to 25.7% in the last decade. The PSCs can be made at low-temperature processes, which means we can apply them on flexible substrates. The best PCE on flexible substrate is 22.4% so far. However, flexible perovskite solar cells (FPSCs) with high PCEs are all made in small areas (＜0.1 cm2) still difficulties to be overcome on the road toward commercialization, and monolithic integration is one of the key issues. In this study, we developed laser patterning technology based on a nanosecond pulsed laser to fabricate PVSK solar modules on the flexible substrate.
Perovskite solar modules are fabricated through a monolithic integration method, which is established by three scribing lines of P1, P2, and P3 by laser patterning method. P1 insulates the bottom electrode and defines the width of each sub-cell. P2 scribes absorber layer and allows top and back electrodes to connect and form a current flow path. P3 separates the top electrode, and finishes connection of sub‐cells in series. A nanosecond pulsed laser with a wavelength of 532 nm is used with the advantage of low cost compared with picosecond or femtosecond lasers. By adjusting the laser power density and pulse overlap ratio to optimize the scribing result, we investigated the effect of P1 scribing line on coating quality of PVSK layer and P2 scribing line on contact resistance between top and bottom electrodes. The wavelength of 532 nm is selected because of high absorption of PVSK layer and low absorption of TCO layer. To improve the PCE of PSCs, we add a modification layer on the hole transport layer. It shows that open circuit voltage and short circuit current are increased and the PCEs rise from 12.7% and 7.9% to 14.4% and 10.8% on the small area (0.09 cm2) glass substrate and flexible substrate, respectively. Therefore, we use these as control samples for comparison to subsequent module processes.
Finally, a mini‐module with two sub-cells was fabricated on the 2×2 cm2 flexible substrate by a spin coating method. The module efficiency based on active area of 1.0 cm2 is 10.8% with the fill factor of 60.1% on flexible substrates. In conclusion, we have successfully demonstrated all laser patterning technology to fabricate flexible perovskite solar modules, and make possible the large-area and large‐scale flexible perovskite solar modules.

並列關鍵字

flexible perovskite solar module ； all laser scribing ； nanosecond pulse laser

參考文獻

[1] T. Stein. "Carbon Dioxide Now More than 50% Higher than Pre-Industrial Levels." National Oceanic and Atmospheric Administration. https://www.noaa.gov/news-release/carbon-dioxide-now-more-than-50-higher-than-pre-industrial-levels (accessed Dec., 2022).

[2] F. Haase et al., "Laser Contact Openings for Local Poly-Si-Metal Contacts Enabling 26.1%-Efficient POLO-IBC Solar Cells," Solar Energy Materials and Solar Cells, vol. 186, pp. 184-193, 2018.

[3] "Best Research-Cell Efficiency Chart." NREL. https://www.nrel.gov/pv/cell-efficiency.html (accessed Dec., 2022).

[4] A. Kojima, K. Teshima, Y. Shirai, and T. Miyasaka, "Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells," Journal of the American Chemical Society, vol. 131, no. 17, pp. 6050-6051, 2009.

[5] W. Ke and M. G. Kanatzidis, "Prospects for Low-Toxicity Lead-Free Perovskite Solar Cells," Nature Communications, vol. 10, no. 1, p. 965, 2019.