Abstract
摘要:本計劃以低成本、溶液製程之製備方式,進行有機無機混成薄膜太陽能電池之研究。利用不同的結構、加入功能性中介層修飾元件,配合有機/無機之介面研究,封裝技術的改良,以及混摻結構的太陽能電池的創新研究,進行一系列對有機無機太陽能電池的研究及改良。
在製程改善方面我們利用表面改質的方式,將二氧化鈦表面置換上導電的有機寡聚物分子,在有機無機混摻介面中有效降低載子的再結合率並且提供較佳的電子注入速率。此外,在開發新型太陽能電池上,我們發現氟化添加物及無機低能隙奈米粒子Cu2S添加物使混成太陽能電池效率提升至4.3%。而高分子PCPDT-ID及P4TI的合成成功,使太陽能電池效率達5.6%。為了更充分利用太陽光譜,我們針對同時具有兩種不同吸光波段的串疊型有機太陽能電池進行研究,目前串疊型有機太陽能電池效率已達6.2%。
在三明治倒置型高分子太陽能電池中,首先我們使用數種溶液製程的氧化中介層於 P3HT:PCBM系統,以提升元件轉換效率與穩定度。在新型的 P3HT:ICBA 新型主動層系統中達5.61%為當時倒置結構的世界記錄。而在low band-gap元件系統研究中,我們與工研院合作的系統在元件完成17500小時後效率仍保有95%以上。而我們具奈米結構的氧化鋅奈米柱結構,來強化有機層的載子傳輸,已在有機高分子系統中超過7%。另外,利用矽奈米線的抗反射效果及增加接觸面積,矽奈米線有機導電膜之太陽能電池,目前元件已可達到 9.56%之高效率,而在矽奈米洞有機太陽能電池更有超過10%轉換效率。
在無機有機介面分析使用本實驗室特有的UPS技術,分析太陽能電池所使用之薄膜介面。我們研究了熱退火機制。經介面分析,使用純鋁陰極的元件退火後,明顯的P3HT能階變化促使元件的開路電壓大增。此外,我們研究並採用近來廣為受歡迎的熔膠凝膠氧化鋅電子傳輸層,由於此薄膜層具有優異的電子傳輸能力。接著,開始著手研究在OLED中被使用之各式緩衝層材料,如電子傳輸層OXD-7、TAZ、BCP、PBD、BPhen;電洞 傳輸層TCTA、NPB、TAPC等,應用於太陽電池中因能階匹配差異對元件Voc之影響。
在封裝技術方面,我們開發高水氧阻絕效果的「透明可撓低溫封裝技術」。有機無機多層交疊的薄膜可以提供很好的水氧阻絕屏障,研究中為了實現單一製程、低溫與低成本的薄膜封裝,開發單層有機無機混成膜,同時引入有機前趨氣體與氧氣在室溫下以電漿輔助化學氣相沉積法製備薄膜。研究發現製程中氧氣流量增加或沉積功率增加時,混成膜中親水的Si-O-Si 鍵結明顯逐漸增加。在光學性質方面,混成膜之可見光平均穿透率可達90%以上。在阻水性質方面,通入氧氣後無機鍵結的增加能有助於提升混成膜的阻水效果。結果顯示製備厚度為1.5μm的封裝膜其水氣滲透率可達~3.6 10-6g/m2-day。
Abstract: We focus on the organic/inorganic thin film solar cells based on low-cost and solution process. The performance of solar cells was improved by different device structure and inserting functional interlayer.
We used the surface modification method to replace insulating ligands by conductive oligomer molecules on TiO2 nanorods. We found the device performance was improved after adding fluorine additives and Cu2S nanocrystals. Furthermore, the low bandgap polymer PCPDT-ID and P4TI were synthesized, and the device performance had achieved 5.6%. Finally, we developed the tandem organic polymer solar cell and gave 6.2% high power conversion efficiency.
In sandwiched structure of system P3HT:ICBA, we fabricated devices in inverted structure and reached 5.61% which is the world record in that time. In low band-gap system, we cooperate with ITRI, the polymer system with over 95% of maximum PCE even after 17500 hours of fabrication. Furthermore, we grow ZnO nanorod structure to enhance the carriers extraction and reached over 7% efficiency in polymer band-gap system. Finally, the organic/silicon nanowire and nanohole solar have 9.56% and over 10% high efficiency.
We also analyze the organic thin films of solar cells by UPS. The large downward shift of the HOMO level of the active layer was observed during annealing, especially with Al coverage, which would directly contribute to the increase of Voc in solar cells using post-annealing process. Then, several kinds of small molecules cathode buffer layer were investigated, including electron transporting layers and hole transporting layers.
Thin film encapsulation technology with excellent permeation barrier property is highly desirable for organic electronic and flexible electronic applications. We develop a single-layer SiOxNyCz encapsulation thin film deposited from a gas mixture of HMDSZ or HMDSO and oxygen by PECVD at room-temperature. An optimal WVTR of 3.6×10-6g/m2day is demonstrated for a 1.5um-thick hybrid thin film.
Keyword(s)
有機無機混摻太陽能電池
表面改質
二氧化鈦奈
米桿
有機寡聚物
無機低能隙奈
米粒
子
氟化添加物
低能階高分子
串疊型有機太陽能電池
倒置結構
溶液製程
?
organic/inorganic hybrid solar cell
surface modification
TiO2 nanorods
organic oligomers
nanoparticles
fluorine additives
low bandgap polymer
tandem
inverted structure
solution process
ZnO nanorod
carriers extraction
thermal annealing
thin-fi