Enhancement of CdS nanoparticles’ photoconductive detector by adding TPD conductive polymer

Abstract

CdS nanoparticles have been prepared by a chemical method and deposited as a thin film on both P-type silicon and porous silicon (PS) substrates by spin coating technique as a photoconductive detector. The Hall measurements show that the nanoparticles are n-type with carrier concentration of about (− 5.45 × 1010 cm−3). The response time of the fabricated detectors on Si, PS and (CdS + TPD/PS) substrates was measured (by illuminating the sample with Halogen lamp 250 W) and its values are 5.2 ms, 2.1 ms and 1.3 ms, respectively. The specific detectivity and photoresponsivity of the fabricated detector on PS are found to be (9.9 × 1012 Watt−1 Hz1/2 cm−1 and 0.043 A/W). The surface functionalization of the CdS nanoparticles film deposited on porous silicon (PS) substrate by triphenyldiamine (TPD) has highly improved the photoresponsivity and response time of the detector to 0.059 A/W and 1.3 ms.