Bismuth oxyiodide (BiOI) thin film was deposited using successive ionic layer adsorption and reaction (SILAR) technique under the same molar ratio of bismuth (III) nitrate pentahydrate (Bi(NO3)5H2O) and potassium iodide (KI). The effects of micro and macro structures due to the post-annealing treatment has been studied towards the improved electronic properties of BiOI films. BiOI thin film was perfectly coated without any cracks or pinholes. The as-deposited BiOI film displayed small flakes with flower shape microstructure. The flakes size has increased from ∼0.8 μm to ∼3.2 μm upon annealing at 350 °C, thenceforth shattered with increasing annealing temperature. BiOI films annealed at 350 °C showed a sharper band edge slope with an energy bandgap ∼1.61 eV compared to others annealing temperatures. The single crystalline BiOI film has transformed from tetragonal to tetragonal-orthorhombic polycrystalline with mix Bi5O7I3 and Bi7O9I3 phases after being annealed ≥450 °C. Electronic properties of BiOI were studied in terms of average resistance and conductivity measured using four-probe hall effect measurement. The conductivity value has reached the maximum for sample annealed at 350 °C, owing to the formation of ordered phase in material structure, higher crystallinity, larger flakes sizes, as well as reduction of defects and grain boundaries resistance. When the annealing temperature exceeded 450 °C, the electrical conductivity decreased due to the particle aggregation, sublimation of materials, formation of mix-phase and polycrystalline structure that generated grain boundaries and provided more resistance for electrons flow. The work has demonstrated a better understanding of material issues and some clues on the effect of the thickness, microstructure and structural properties on the electronic properties of BiOI thin film.

Bismuth Oxyiodide (BiOI) has been recognized as a suitable candidate of non-toxic material to replace lead in perovskite solar cells without reducing its performance. BiOI has been synthesized and deposited using modified successive ionic layer adsorption and reaction (SILAR) dip coating method at room temperature on the microscope glass, as a substrate. The microscope glass was dipped consecutively in 0.1M of bismuth(III) nitrate pentahydrate (BiNO3)2.5H2O diluted in nitric acid (HNO3) and 0.05M of potassium iodide (KI) in 50 ml deionized water. This process has been repeated for 30 times and finally the sample was dripped and dried in air. The sample was annealed at various annealing temperature from 350, 400, 425 and 450oC, for 1 hour. The physical observation, morphological and thickness of BiOI thin films have been characterized using field emission scanning electron microscope (FE-SEM) and surface profiler, respectively. From the physical observation, the as deposited BiOI thin film shows a thick layer with dark orange colour. The colour of the film changed to the orange-yellow after annealed at 350oC for 1 hour. It was observed that the film become more yellowish with increasing annealing temperature. SEM images demonstrated that the BiOI thin films have flakes morphology structure with the grain sizes around 1μm. The flakes agglomerates and formed a flower platelet. The agglomeration increased with higher annealing temperature and finally shattered when the BiOI was annealed at 450oC.

This study investigated the difference in muscle activation of the muscles in right handed (RH) and left handed (LH) participants during riding of motorcycle simulator. Five participants (3 RH and 2 LH) with average age of 24.2±0.447 years old were recruited and they were requested to ride the simulator for certain period of times for three days. Two surface electromyogram (sEMG) electrodes were attached to right flexor carpi radialis (RFCR) and left flexor carpi radialis (LFCR) of the participants forearm. Electromyography (EMG) of flexor carpi radialis (FCR) are measured at both hands during the task. The results showed that muscle activation during first 5 minutes of riding task in day 1 of experiment (percentage of maximum voluntary contraction, %MVC) for RFCR in LH (non-dominant) participants was 97.4% and 87.7% in RH (dominant) participants. Therefore, this result indicates that non-dominant person needs to activate more muscle than RH person during control the accelerator throttle while riding.

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