S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Electrical and Computer Engineering (전기·정보공학부) Others_전기·정보공학부
Electrical impedance studies of the effect of a buffer layer on organic bulk-hetrojunction solar cells
- Suman, C. K.; Noh, Seunguk; Kim, Seohee; Lee, Sin-Doo; Lee, Changhee; Lee, Donggu; Park, Jeongho
- Issue Date
- 한국물리학회 = The Korean Physical Society
- J. Korean Phys. Soc. 53, 3278
- Organic solar cells; Bulk heterojunction; Buffer layer; Impedance spectroscopy; Interface; Metal diffusion; Traps
- The effect of a buffer layer on organic bulk hetrojunction solar cells of poly(3-hexylthiophene)
(P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester fullerene derivative (PCBM) has been
studied using impedance spectroscopy in the frequency range between 100 Hz and 1 MHz. The
buffer layer interfaces with a metallic contact and with the organic bulk materials in
effciency and the stability of devices. Thermal annealing of the devices improves the interface
with the buffer layer, thereby lowering the majority and the minority carrier injection voltage.
The photocurrent density-voltage (J-V) characteristics show that the fill factor of the device with
a molybdenum-oxide (MoO3) buffer layer is higher than that of the device with a poly (3, 4-
ethylenedioxy-thiophene):polystyrenesulfonate (PEDOT:PSS) buffer layer. The equivalent circuit
analysis for the PEDOT:PSS and the MoO3 buffer-layer devices shows that the device's capacitance
and resistance for MoO3 is lower than that for PEDOT:PSS under illumination. The effciency of the
thermally-annealed PEDOT:PSS and MoO3 buffer-layer devices are 2.95 and 3.44 %, respectively.
The lower effciency of the PEDOT:PSS buffer-layer devices can be attributed to the formation of
a thin insulator layer at the PEDOT:PSS/P3HT:PCBM interface under illumination.
- 0374-4884 (Print)