Conference article

The electronic transport of CdS nanoparticles (nano-CdS) covered by hydrophilic alkanolamine molecules as surfactants was studied. The nanomaterial was prepared by low-temperature decomposition of cadmium ethylxanthate in hydrophilic solvents like mono-; di- or triethanolamine. The nanoparticles were isolated by precipitation procedures in solid state and they are easy to re-disperse in water systems. Films with nanoparticles were exposed to UV radiation; with the exposure varying in time interval 10 – 60 min. The goal of the work was to study the electronic transport in the array of nanoparticles. The experimental techniques used was the Isothermal charge transient spectroscopy (IQTS) working with the a unique charge transient processor in the sampling range 2 µs – 900 ms with resolving power of about several hundreds of electrons. The second method was the surface photovoltaic method (SPV). Two basic novel phenomena were observed on the film formed by nano-CdS provided with tu surfactant; in I-V characteristics the increase of current was observed with a strong nonlinearity; marking the increased transport via nanoparticles; and the occurrence of charging–discharging phenomena with strong maximum described by the distribution of relaxation times and/or trapping states occurrence. The photoconductivity action spectra agree with the absorption edge of size distributed nanoparticles.

CdS nanoparticles; Alkanolamine surfactants; Isothermal charge transient spectrum; Hybrid solar cells