運用混成結構製作疊層式有機太陽能電池

Abstract

使有機太陽能電池能更完全地吸收太陽能，在本研究中我們在高分子主動層上疊接一小分子元件，且在兩主動層與中間電極銀之間，分別加入碳酸銫及氧化鉬，以幫助高分子層的電子注入及幫助小分子層電洞注入，以達成有效的元件連結。結果發現，在疊接小分子層後，能使原本單一高分子層所不能有效吸收的太陽能光波段 (600~700 nm和400~450 nm)，藉由疊接後的小分子層有效的吸收，使得疊接後的元件在吸收太陽光的能力有整體的提升，且能吸收更寬廣的太陽能光譜。另外，我們發現當疊層式元件的中間電極銀越薄時，整體元件的短路電流、開路電壓與光電轉換效率皆有提升。此外，我們也發現電流匹配(current matching)對於製作疊層式元件是非常重要的關鍵，因為有更佳的電流匹配而使元件能達到更高的開路電壓1.21 V及更高效率(1.81 %)的疊層式有機太陽能電池。

In order to absorb different wavelength of sunlight to extend the absorption of the entire cell over a wider spectral range, we stacked a small-molecular cell on a polymer subcell. Between the two subcells, we deposited Cs2CO3, Ag, and MoO3, to serve as the connecting structure. While the polymer layer mainly absorbs the photons with wavelength less than 600 nm, the small molecular layer exhibited a significant absorption well beyond 600 nm, thereby extending the overall absorption regime. In addition, we found that when the thickness of the silver was thinner, the short circuit current, the open circuit voltage, and the power conversion efficiency of the device were all improved. We also found that “current matching” plays an important role in determining the device efficiency. Both high open circuit voltage (1.21 V) and power conversion efficiency (1.81 %) have been achieved.