Organic Solar Cells Based On P3HT: PC₆₁BM: Morphology And Interface Modification

Nowadays, the search for clean and renewable energy has been driven by thequickly increasing energy consumption and further accelerated by increasing concernsabout carbon emission from fossil fuel-based energy sources. The advantages oflightweight, flexible and cost-effective make organic solar cell one of the mostattractive and promising field. In the last years, the power conversion efficiency oforganic solar cell have developed rapidly and approaching10%.The morphology of the active layer and the metal/organic interface plays anessential role in determining the overall device performance of organic solar cells.Modification of the morphology or inserting a functional interfacial layer candramatically alter the devices’ properties. According to this, we are trying to doresearch about the way to control the morphology and interface of organic solar cellsbased on P3HT:PC₆₁BM.First, we try to figure out the effect of thermal annealing on the performance oforganic solar cells based on P3HT:PC61BM. We fabricated the device with thestructure: ITO/PEDOT:PSS/P3HT:PC₆₁BM/Al. By altering the thermal annealingtemperature and time, we find that the higher performances are obtained after thermalannealing. After thermal annealing treatment140℃for15min, the devices exhibit aVoc of0.62V, short-circuit current （Jsc） of7.52mA/cm², fill factor （FF） of0.59, andpower conversion efficiency （PCE） of2.76%under one sun of AM1.5solar simulatorillumination （100mW/cm²ï¼‰. We also evaporate a LiF thin layer between Al and activelayer. With a2nm LiF layer, we get the result of Voc of0.64V, short-circuit current（Jsc） of9mA/cm², fill factor （FF） of0.66, and power conversion efficiency （PCE） of3.78%under one sun of AM1.5solar simulator illumination （100mW/cm²ï¼‰. Second, we systhesis the zinc oxide nanoparticles dissolved in methanol and wespin coat the zinc oxide nanoparticles as an cathode interface. The device with thezinc oxide layer exhibit a Voc of0.64V, short-circuit current （Jsc） of9.58mA/cm²,fill factor （FF） of0.60, and power conversion efficiency （PCE） of3.70%under onesun of AM1.5solar simulator illumination （100mW/cm²ï¼‰. We also do UV-vis,TEMand AFM to characterize the zinc oxide nanoparticles.