1P-242 : New solution-processable triphenylamine derivatives for efficient organic solar cells applications

Small molecules TPASi-OH, TPAB, comprising the same moeity TPA (Triphenylamine) and different trimethylsilane and fluorodimesitylborane were designed and synthesized as hole-transporting materials in organic solar cells. The triphenylamine based derivative TPASi-OH and TPAB exhibited a short-circuit current density (Jsc) of 14.99 mA/cm2, 12.63 mA/cm2 and an open-circuit voltage (Voc) of 0.74 V, 0.66 V respectively. Compared to the bare ITO substrate, the TPA-si film reveals a slight decrease in transmittance when the wavelength is shorter than 400 nm which is contributed from the absorbance of TPASi-OH film. Consistently , the TPASi-OH HTM exhibit better transmittance in the visible range than the PEDOT:PSS. The transmittance of TPASi-OH film is above 98%. The power conversion efficiency (PCE) of the Organic solar cells based on TPASi-OH and TPAB are about 7.10% and 4.01%, respectively, in which the efficiency of former is comparable to that of PEDOT:PSS based cell. A high conversion efficiency of 7.10% was realized by a TPASi-OH buffered device employing a low band gap polymer PTB7 as the active material, which showed 7.10% efficiency enhancement over control devices.