_Article_  
**Fabrication and Microelectronic Properties of Hybrid Organic-Inorganic (poly(9,9, dioctylfluorene)/p-Si) Heterojunction for Electronic Applications**  
**[PERSON] 1,*()**, [PERSON] 1, [PERSON] 2, [PERSON] 3, [PERSON] 1, [PERSON] 4 and [PERSON] 5  
Department of Physics, Faculty of Physical and Numerical Sciences, Abdul Wali Khan University Mardan, Mardan 23200, Khyber Pakhtunkhwa, Pakistan, [EMAIL_ADDRESS] (M.I.); [EMAIL_ADDRESS] (M.Z.)  
Department of Electronics, Jinnah College for Women, University of Peshawar, Peshawar 25120, Khyber Pakhtunkhwa, Pakistan; [EMAIL_ADDRESS]  
Institute of IR 4.0, Universit Kebangaan Malaysia, UKM Bangi, Selangor 43600, Malaysia; [EMAIL_ADDRESS]  
Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor 43600, Malaysia; [EMAIL_ADDRESS]  
Department of Electric, Electronics and System Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; [EMAIL_ADDRESS]  
Correspondence: [EMAIL_ADDRESS] Tel.: +92-937-843-377  
Received: 22 September 2020; Accepted: 23 October 2020; Published: 10 November 2020  
We report on the microelectronic characteristics of a novel hybrid heterojunction device based on a solution processable semiconducting polymer poly(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,/N0-diphenyl)-N,/N'di(p-butyl-oxy-phenyl)-1,4-diamino-benzene) (PFB) and p-type silicon (p-Si). The PFB/p-Si heterojunction is prepared by spin coating 20 mg/mL solution of PFB in chloroform on the precleaned polished surface of p-Si substrate. Thermal evaporation of silver (Ag) electrode on top of PFB completes the fabrication of the Ag (90 nm)/PFB (180 nm)/p-Si heterojunction device. Morphology of PFB thin film is studied by using an atomic force microscope (AFM) and scanning electron microscope (SEM), which reveals grains are randomly distributed with slightly different grain sizes and shapes. It leads the film to form nonuniformity and some roughness in its topography that results in limiting the current (_I_) flow across the film/interface with p-Si. Ultraviolet (UV-vis) absorption and X-ray diffraction (XRD) spectra are measured for optical bandgap and crystal structure analysis of PFB. The key microelectronic parameters--rectification ratio (RR), ideality factor (_n_), barrier height (\(\varPhi_{b}\)), series resistance (\(R_{s}\)) and reverse saturation current (\(I_{0}\))--of the Ag/PFB/p-Si heterojunction are found from current-voltage (_I_-_V_) characteristics at room temperature (300 K) in dark conditions (\(\approx\)0 lux). The Ag/PFB/p-Si heterojunction device exhibits improved microelectronic parameters when compared to those of earlier reported devices that were prepared in the same configuration. This improvement in the device parameters reveals enhancement in the microelectronic properties across the interface/depletion region of the Ag/PFB/p-Si device, which can be attributed to the remarkable electronic properties of PFB such as its relatively high hole mobility and better charge carriers' conduction. The charge transport mechanisms through the device is also studied. Having the smaller values of \(I_{0}\approx 7\times 10^{-10}\) A and \(n\approx 3.23\), as well as higher shunt resistance (\(R_{sh}\)) of 32 G\(\Omega\) for the Ag/PFB/p-Si device suggest its potential for many electronic and optoelectronic applications.**  
**Keywords:** poly-(9,9, dioctylfluorene); current-voltage (_I_-_V_) characteristics; organic heterojunction; microelectronic properties; thin film characteristics