Structural, photoluminescent and electrical properties of CdTe films with different compositions fabricated by CMBD

A Study of Photo-response and Photoelectrical properties of Cadmium Telluride Thin Film

“…The I-V curve has identified two type of conduction mechanism; (i) At low biasing voltage, the conduction mechanism are ohmic and (ii) At higher voltage (more than transition voltage, V X ), the I-V curves nature are non linear region, the conduction mechanism is space charge limited conduction (SCLC) due to existence of charge traps [27][28][29]. However, the real nature of the traps present in the materials under study depends on the type of the traps and their position with respect to the Fermi level [30,31]. The conduction mechanism in CdTe thin film is governed by grain boundaries defect states and their concentration which dependent on film growth condition.…”

Thin Film Cadmium Telluride Solar Cells

“…34,[39][40][41] Typically, 5-10 mm thicknesses for CSS-CdTe are required 3,[43][44][45][46][47] in order to avoid the issue of pinholes that may propagate through the CdTe layer to the back contact. Due to the high absorption coefficient, a CdTe layer thickness of 2 mm is sufficient [48][49][50][51][52] to absorb the majority of photons in the visible and near infrared region, in which CdTe solar cells are active. Carriers that are generated far into the CdTe absorber layer have more chance of recombination as they diffuse towards the junction.…”

“…Deposition under Te-rich conditions at the high temperatures ($500 C), typically employed in CSS, [11][12][13]53 induces the p-type character of the growing layer due to intrinsic doping by the formation of cadmium vacancy (V Cd À ) acceptor centres, as well as interstitial Te (Te i ). 24,51,54 Te-rich conditions favouring formation of V Cd À and Te i have also been explored 9,10 using the MOCVD process and found at the time to result in optimum solar cell performances relative to more stoichiometric, or Cd-rich conditions. Other growth conditions, such as annealing ambient, can affect the intrinsic doping characteristics.…”

“…51 ) complexes that may also act as deep level traps. Under Cd-rich conditions, there is a strong likelihood that Cd i 2+ or V Te 2+ will form introducing donor levels into the CdTe, 56 which will compensate for any extrinsic dopants used to obtain p-type character.…”

Studies on CdTe films deposited by pulsed laser deposition technique

“…Due to its specific advantages, this II-VI compound is one of the primary candidates in the field of photovoltaic energy. These include the near ideal band gap energy of 1.45 eV, a high optical absorption coefficient of over 99% of the incident sunlight with only about 2 mm of active thickness [7,8].…”