Influence of plasma parameters and substrate temperature on the structural and optical properties of CdTe thin films deposited on glass by laser ablation

Abstract

In the pulsed laser deposition of thin films, plasma parameters such as energy and density of ions play an important role in the properties of materials. In the present work, cadmium telluride thin films were obtained by laser ablation of a stoichiometric CdTe target in vacuum, using two different values for: substrate temperature (RT and 200 °C) and plasma energy (120 and 200 eV). Structural characterization revealed that the crystalline phase can be changed by controlling both plasma energy and substrate temperature; which affects the corresponding band gap energy. All the thin films showed smooth surfaces and a Te rich composition.

CdTe:Sn thin films deposited by the simultaneous laser ablation of CdTe and Sn targets

“…Figure 9 shows the PL spectra of the films. As it can be observed, the CdTe sample exhibits a band centered at 1.5 eV, which agrees with an emission corresponding to a near edge transition for CdTe [16]. As Sn ion density increases, the near edge emission slightly shifts to higher energies, which is in agreement with UV-vis measurements.…”

“…The Cd/Te ratio was calculated from XPS measurements by considering the binding energy signals for Cd 3d 5/2 and Te 3d 5/2 . The CdTe film grew with a Te excess, this effect has been observed before for films grown at similar plasma conditions [16]. However, when the CdTe and Sn plasmas are combined, the Cd/Te ratio was modified; values above 8×10 11 cm −3 , yield films with Cd excess.…”

“…These films have been grown using deposition techniques such as atomic layer epitaxy [12], molecular beam epitaxy (MBE) [11], sputtering [5,13], closed space sublimation [14,15] and Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. pulsed laser deposition (PLD) [1,6,16]. The PLD technique can produce high quality layers of many different materials, with the possibility of obtaining stoichiometric films with excellent physical properties.…”

“…The PLD technique can produce high quality layers of many different materials, with the possibility of obtaining stoichiometric films with excellent physical properties. It has been demonstrated that the diagnosis of the plasma produced by the laser ablation of the target, allows a precise control of the structural properties even at room substrate temperature for different materials [16,17]. When the plasma parameters (mean kinetic ion energy and density) are measured and thus, monitored, highly reproducible experiments can be performed and the properties of the growing films can be precisely controlled; in addition, the combination of two laser produced plasmas, offers the possibility of synthesize alloys, compounds, composites or doped materials [18][19][20].…”

ZnO thin films grown at different plasma energies by the laser ablation of metallic Zn with a 532 nm wavelength

“…One of the most significant differences between ZnO thin films deposited by PLD from a Zn target and ZnO targets is the thickness; deposited layers by ablating of Zn metallic targets are usually thinner [14,15], this can be an advantage in the fabrication of nanoscale devices. Dynamics of the plasma in PLD method have been used to modify the physical properties of the deposited materials [16][17][18]. However, there are few studies related to the control of the plasma parameters at room temperature (RT); mean kinetic energy (E k ) and plasma density (N p ), in the growth of the ZnO thin films.…”