Microbial synthesis of semiconductor CdS nanoparticles, their characterization, and their use in the fabrication of an ideal diode

Cadmium sulfide nanoparticles were synthesized intracellularly by a Schizosaccharomyces pombe strain when challenged with 1 mM cadmium in solution. The nanoparticles, a known semiconducting material, exhibited an absorbance maximum at 305 nm. X‐ray scattering data showed that the nanoparticles had a Wurtzite (Cd16S20)‐type hexagonal lattice structure and most of the nanoparicles were in the size range of 1–1.5 nm. The nanoparticles were used in the fabrication of a heterojunction with poly (p‐phenylenevinylene). The diode exhibited ∼75 mA/cm2 current at 10 V when forward biased and the breakdown occurred at ∼15 V in the reverse biased mode. These characteristics are considered ideal for a diode. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 583–588, 2002.