Solution-processed solar-charging power units made of organic photovoltaic modules and asymmetric super-capacitors

摘要

Organic photovoltaics with the properties of flexibility,portability,and printability are ideal candidates for low-power-consumption electronics such as the Internet of Things under indoor light conditions. In this work,an all solution-processed integrated photocapacitor (IPC) consisting of an organic photovoltaic module (OPVM) and an asymmetric super-capacitor (ASC) is demonstrated. The OPVM poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[l,2-b:4,5-b′]dithiophene)-co-(l3,-di(5-thiophene-2-yl)-5,7-bis(2-ethylhexyl)benzo[l,2-c:4,5-c′]dithiophene-4,8-dione)] (PBDB-T):3,9-bis(2-methylene-(3-(l,l-dicyanomethylene)-indanone)-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′d′]-s-indaceno[l,2-b:5,6-b-]-dithiophene(ITIC) with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the top electrode delivers a high power conversion efficiency of 6.7% with a voltage of 4.3 V (1 Sun). The ASC based on PEDOT∶PSS and Ti_3C_2T_x electrodes shows a wide operation window of 1.5 V in the aqueous electrolyte with a high energy density of 28.7μW h cm~(-2). Consequently,the IPC achieves a high output voltage of 3 V and outstanding overall efficiency of 6.0% (45 000 lx),which shows excellent stability as the solar-charging power unit under room light (500 lx). Synergizing energy harvest and storage in a solution-processed robust,lightweight,low-cost organic IPC enables this solar-charging power unit wide potential applications in low-power-consumption portable electronics.