Optical and Electrical Characterization of (002)-Preferentially Oriented n-ZnO/p-Si Heterostructure

Abstract

In this paper, preferentially oriented (002) ZnO thin lms have been grown on Si (100) and glass substrates using radio frequency magnetron sputtering. The dependence of the quality of the ZnO thin lms at dierent substrate temperatures on the growth is studied. A ZnO thin lm with c-axis-oriented würtzite structure is obtained at a growth temperature from 200 to 400• C. X-ray diraction shows that the full width at half maximum θ2θ of (002) ZnO/Si is located at approximately 34.42• , which is used to infer the grain size that is found to be 17 nm to 19.7 nm. The FWHM is 9.5• to 8• in rocking curve mode, from which the crystalline quality has been determined. The texture degree demonstrates the improvement in quality with the increase of substrate temperature, which is best at 400• C. The band gap extracted by UV transmittance spectrum has been identied as 3.2 eV at 400• C. The electrical characteristics via CV and IV measurements on the basis of the heterojunction thermal emission model conrm the domination of high-density grain boundary layer existing at the interface. The transport currents indicate to the presence of space-charge-limited current and trap-charge-limited current mechanisms.

Effects of Deposition Time on the Morphology, Structure, and Optical Properties of PbS Thin Films Prepared by Chemical Bath Deposition

“…The increase in the film thickness leads to an improvement of the crystalline quality. This is attributed to the strain in the film introduced during the deposition [34], that is, the thicker films suffer less strain than the thinner ones. This comes in a good agreement with our results where thicker films have lower stress value and better quality.…”

“…It has been observed that the average transmittance of the studied samples in the visible range decreased from 40% to 20% with increased film thickness. The optical transmittance provides useful information about the optical band gap of the semiconductor [34] as shown in Figure 6.…”

Oxygen Effect on Structural and Optical Properties of ZnO Thin Films Deposited by RF Magnetron Sputtering

“…The optical transmittance provides useful information about the optical band gap of a semiconductor 31 . It was observed that the average transmittance of samples in the visible and near infrared range is varied from 80% to 92%.…”

Syntheses, Structural and Nonlinear Optical Characteristics of ZnO Films Using Z-Scan Technique

“…Also, it has been demonstrated that the increased in substrate temperature accompanied with improvement of ZnO film quality, could be led to extract the band gap of 3.2 eV at 400°C by recording the UV-Vis transmittance spectra. The C-V and I-V measurements on the basis of the heterojunction thermal emission model have confirmed that the domination of high-density grain boundary layer existing at the region of interfacing [6].…”

“…Also, new thin films were prepared by DC magnetron sputtering, it was found that the films have a corrosion resistance with high microhardness value [5]. The NLO properties of ZnO films are currently subject to specific work, in response to satisfy the industrial need for optoelectronic devices, it could be operated at a short wavelengths range [6]. Pure and doped nanocrystalline ZnO films have shown high second-harmonic efficiency and this makes the ZnO to be used as efficient optical modulator [7].…”