Highly Responsive Al/PTB7/Si/Al Vertical Structure-Based White Light Photodetector Using FTM Method

This letter reports a p-type Poly [[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophenediyl]] (PTB7) thin film based Al/PTB7/Si/Al vertical structure for white light detection application. The thin film of PTB7 polymer was deposited via a low-cost and facile floating-film transfer method (FTM). The morphology of the PTB7 film is analyzed by tapping mode Atomic Force Microscopy (AFM) which gives an average surface roughness as ~0.703 nm. The maximum responsivity and detectivity of the fabricated device were obtained as ~146.13 mA/W and
$\sim 4.137\times 10^{10}$
Jones at ~0.228 mW/cm
²
white light intensity under a reverse bias of −2 V. The rise/fall time of the fabricated sensing device was measured as ~0.016/~0.112 s respectively.