Author(s)

Md. Shahinul Islam^1*, Md. Golam Saklayen¹, Md. Ferdous Rahman², Hartmut Baerwolff³, Abu Bakar Md. Ismail¹

¹Department of Applied Physics & Electronic Engineering, Rajshahi University, Rajshahi, Bangladesh.
²Department of Electronics and Telecommunication Engineering, Begum Rokeya University, Rangpur, Bangladesh.
³Department of Analog & Optoelectronics, Cologne University of Applied Sciences, Cologne, Germany.

This article presents the investigation on very thin Lanthanum Fluoride (LaF₃) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) polymer blend at 1:1 ratio. Electron-beam evaporation at room temperature was used to deposit 3 and 5 nm thick LaF₃ layer. A very smooth surface of LaF₃ with an average roughness of 0.2 nm has been observed by the Atomic Force Microscope (AFM) that is expected to prevent diffusion of cathode metal ion through it and thereby enhance the lifetime and stability of OSC. Huge enhancement of J_SC and V_OC was also observed for 3 nm-thick LaF₃ CBL. Several excellent features of the LaF₃ layer such as, transporting electron through tunneling, blocking of holes to the cathode, minimizing recombination, protecting the photoactive polymer from ambient oxygen, and reducing degradation/oxidation of any low work function layer at the cathode interface, might have contributed to the performance enhancement of OSC. The experimental findings indicate the promise of LaF₃ to be an excellent CBL material for OSC.

Organic Semiconductor, Photoactive Polymer, Organic Solar Cell, Bulk Heterojunction Solar Cells, Cathode Buffer Layer, Lanthanum Fluoride, Spin Coating, E-Beam Evaporation

Islam, M. , Saklayen, M. , Rahman, M. , Baerwolff, H. and Ismail, A. (2014) Investigation on Lanthanum Fluoride as a Novel Cathode Buffer Material Layer for the Enhancement of Stability and Performance of Organic Solar Cell. Optics and Photonics Journal, 4, 280-287. doi: 10.4236/opj.2014.410027.