Preparation of Semiconducting Thin Films
Abstract:
One is to determine the gap energy of cadmium sulfide semiconductor thin film using the equation: Eg = h.c/ is the signal of the long wavelength limit of the absorption peaks (measured in the lab). The reaction between cadmium sulfide and NH3, in the presents of thiourea yield a of 579(nm). The % error of the reaction is 1.24%.
Introduction:
There are 3 types of metals for electricity conducting: metallic conductor, semiconductor, and superconductor. Metallic conductors allow the free flow of ions and electrons through a sample; and its conductivity decreases as the temperature increases.
Semiconductors allow the flow of both ions and electrons through the sample but not completely free; and its conductivity increases with increasing temperature. Superconductors are a class of metallic conductor whose resistance drops to zero suddenly below a certain critical temperature.
The energy levels in semiconductors are divided into two bands, valance bands and conduction bands. At absolute zero, the semiconductors’ valance bands are fully filled with electrons and partially filled with electrons in the conduction bands. For the conductors, the valance bands are partially filled with electrons and completely filled with them in the conduction bands. A band gap is the value of the energy for which there is no molecular orbital (the gap size between the valance and conduction bands). Electrons are the available conduction carriers which can get excited and go cross the band gap if they have enough thermal energy. The semiconductors’ band gaps are usually thinner than the conducting ones. In this experiment, one is to prepare a cadmium sulphide semiconducting film on the glass slides. The transition of electrons from the valence band to the conduction band can be achieved by the absorption of electromagnetic radiation, if this energy is equal to or larger than Eg. The excited electrons reaching its new energy level can absorb
One is to determine the gap energy of cadmium sulfide semiconductor thin film using the equation: Eg = h.c/ is the signal of the long wavelength limit of the absorption peaks (measured in the lab). The reaction between cadmium sulfide and NH3, in the presents of thiourea yield a of 579(nm). The % error of the reaction is 1.24%.
Introduction:
There are 3 types of metals for electricity conducting: metallic conductor, semiconductor, and superconductor. Metallic conductors allow the free flow of ions and electrons through a sample; and its conductivity decreases as the temperature increases.
Semiconductors allow the flow of both ions and electrons through the sample but not completely free; and its conductivity increases with increasing temperature. Superconductors are a class of metallic conductor whose resistance drops to zero suddenly below a certain critical temperature.
The energy levels in semiconductors are divided into two bands, valance bands and conduction bands. At absolute zero, the semiconductors’ valance bands are fully filled with electrons and partially filled with electrons in the conduction bands. For the conductors, the valance bands are partially filled with electrons and completely filled with them in the conduction bands. A band gap is the value of the energy for which there is no molecular orbital (the gap size between the valance and conduction bands). Electrons are the available conduction carriers which can get excited and go cross the band gap if they have enough thermal energy. The semiconductors’ band gaps are usually thinner than the conducting ones. In this experiment, one is to prepare a cadmium sulphide semiconducting film on the glass slides. The transition of electrons from the valence band to the conduction band can be achieved by the absorption of electromagnetic radiation, if this energy is equal to or larger than Eg. The excited electrons reaching its new energy level can absorb