The synthesis of 4,4′-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis( N , N -diphenylaniline) organic semiconductor and use of it as an interlayer on Au/n-Si diode

In the present study, firstly, a 4,4′-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis( N , N -diphenylaniline) (FC) organic compound was synthesized and its structural and optical characterization were carried. Then, the effect on the device of the FC thin film prepared between n-type silicon substrate and gold metal by the spin coating technique was reported. The ideality factor ( n ), barrier height ( Φ_B ) and series resistance ( R_s ) values of the prepared structure from the I - V data have been found at 1.08, 0.78 eV and 240 Ω at room temperature (300 K), respectively. According to the Gaussian distribution of the barrier height obtained from the various temperature ranges (220–380 K), the Φ_b0 and A* values from the ordinate intercept and the slope of the modified Richardson curve of ln( I_0 /T^2) - ( q^2σ_s^2 /2k^2 T^2) versus 1/ T plot which has been found to be 0.97 eV and 114 A/cm 2 K 2 , respectively. Results indicate that the high barrier height is achieved for the Au/FC/n-Si metal–organic layer-semiconductor diode as compared to the Au/n-Si metal–semiconductor (MS) diode.