有機電洞傳輸層對硒化鉛光伏特元件之影響

Abstract

本篇論文探討PEDOT:PSS電洞傳輸層對PbSe量子點多層膜光伏特元件之影響。藉由掃瞄式電子顯微鏡與原子力顯微鏡分析得知，添加PEDOT:PSS可使PbSe量子點多層膜光伏特元件表面型態較為平滑。此外，經由光伏特元件之電流-電壓特性曲線量測發現，隨著PbSe量子點第一激發吸收波長的增加，粒徑變大，元件之開放電壓有變小的趨勢，而添加PEDOT:PSS使得PbSe薄膜元件的開放電壓有增加的現象，且太陽能元件轉換效率從1.35%提升至2.14%，比沒有添加PEDOT:PSS之元件增加了59%。根據量測外部量子效率，得知此元件在可見光與紅外光區皆有光電流響應，因此選用830 nm的紅外光雷射光源量測紅外光轉換效率，結果得知添加PEDOT:PSS之紅外光元件轉換效率從1.6% 提升至2.9%。在元件穩定性方面，分別持續照射模擬太陽光與紅外光雷射光源數百分鐘，當效率衰減至原先之80%時，添加PEDOT:PSS之元件所經歷的時間為沒有PEDOT:PSS之元件的六倍，得知PEDOT:PSS可使得PbSe量子點多層膜光伏特元件維持長時間的元件壽命。

Here, we report a thin poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) hole transport layer enhances the performance of PbSe quantum dots (QDs) photovoltaic devices - solar and IR power conversion efficiencies of 1.35% and 1.6%, representing a relative increase of 2.14% and 2.9% over that of a standard PbSe QDs device, respectively. Scanning electron microscope and atomic force microscope show the PbSe QDs films incorporating an organic PEDOT:PSS hole transport layer become smoother than the PbSe QDs films without PEDOT:PSS layer. Current density–voltage measurement displays the increase in open-circuit voltages for the PbSe QDs devices incorporating PEDOT:PSS hole transport layer, and the decrease in open-circuit voltages upon increasing the QD size was due mainly to the corresponding rising of the valence band and the narrowing of the band gap of the PbSe QDs. Moreover, the device life time, as measured by the degradation time to 80% of the normalized efficiency, for the PbSe QDs device incorporating a PEDOT:PSS hole transport layer is prolonged six-fold as compared to that for a standard PbSe QDs device.