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Good thermoelectric performance is being sought to face major problems related to energy, especially in the concern of the usage of energy on environmental impact. In this work, we investigate the underlying mechanism to enhance the thermoelectric performance of bismuth selenide (Bi2Se3) by employing density functional theory (DFT) followed by the Boltzmann transport equation under relaxation time approximation. The structural, electronic, and thermoelectric properties were calculated and analyzed. From the analysis of combined results of thermoelectric properties and electronic properties as the function of the Fermi level, we found that the power factor of Bi2Se3 is improved by increasing electrical conductivity that contributed by the large density of states and light effective mass of charge carriers. The figure of merit, on the other hand, is enhanced by increasing Seebeck coefficient that contributed by heavy effective mass and decreasing thermal conductivity that contributed by low density of states. We also found that both power factor and figure of merit can be improved through n-type doping at 300 K and p-type doping at higher temperature (400 K and 500 K).

The utilisation of teaching aids is one of the factors that contribute to a teacher’s attainment of effective teaching objectives and can be used by students. The purpose of this study was to 1) develop an Optical Learning Module (MPO) using Genially for Optical Topic and 2) determine the usability of the MPO created using Genially to UPSI trainee teachers. This study was designed using ADDIE Model and Behaviourism Theory. This study employs random sampling approach for 40 trainee teachers to fill the questionnaire and two UPSI Physics lecturers to validate the questionnaire and module’s usability. The instrument used was a self-created questionnaire classified into three sections: the assigments, the content of the module, and the user’s perception of the Genially based module. The percentage of agreement, mean, and standard deviation were used to analyse the result that was acquired from the questionnaires using descriptive statistics in SPSS version 25. The result showed that the module has high validity with ~97% expert agreement. The mean score for the perception of this module was 3.2988. The findings demonstrated that the module is useful as one of the tools in teaching for trainee teachers. As a result, this study shows that the utilisation of this module could contribute to improving interest in learning and assist trainee teachers, particularly in Optics.

Cadmium telluride (CdTe) solar cells have attracted a lot of interest in recent years, attributed to their low cost and eco-friendly fabrication technique. However, the back contact is still the key issue for further improvement in device performance due to the work function difference between p-CdTe and metal contacts. In this study, the interatomic characteristics of zinc telluride (ZnTe) and Cu-doped ZnTe (ZnTe:Cu) as a back surface field (BSF) in CdTe structure is investigated using first-principles density functional theory (DFT) to overcome the Schottky barrier in CdTe solar cells. The incorporation of different doping levels of copper (Cu) in ZnTe on an atomic scale, where Zn 1− x Te:Cu x ( x  = 0, 2, 4, 6, 8, and 10) as the potential back surface field layers is investigated. The effect of doping concentration on electrical characteristics such as bandgap structure and density of states (DOS) were examined via ab initio with the Hubbard U (DFT + U) correction. The results showed an interesting gradual decrease in the bandgap energy of ZnTe from 2.24 eV to 2.10 eV, 1.98 eV, 1.92 eV, 1.88 eV, and 1.87 eV for the incremented value of Cu content of 3.13%, 6.25%, 9.38%, 12.50%, and 15.63%, respectively. Accordingly, it has been found that controlling of the effective copper doping, i.e., concentration, is crucial for developing efficient back contact junctions for high-efficiency CdTe thin-film solar cells.

This study aimed to develop and evaluate the usability of a Force and Motion Digital Game using Game-based learning (GBL) among physics student teachers in tertiary education. The research design of this study was developmental research based on the Instructional Design-Digital Game Based Learning model (ID-DGBL model). A group of samples of 21 student teachers were chosen using cluster sampling methods for the usability test of the developed game. A questionnaire instrument was used to collect the usability data of the developed game adapted from the user testing on game. The data collected was analysed using descriptive statistics such as percentage, mean and standard deviation. Based on the findings, the percentage of expert’s agreement for the developed game and questionnaire in the validity process were 100%, while the overall mean score for the usability of the developed game was 4.74 (SD=0.33) including the constructs of Game Usability (GU), Playability (PL), and Learning Content (LC). In the conclusion, the developed game was valid and reliable, as well as suitable to be used as game-based learning for the topic of Force and Motion. In the implication, the developed game was able to complement the conventional learning process by using the game-based learning.