In this paper, we report on a homemade optical spectrometer using diffraction grating and image processing techniques. This device was designed to produce spectral images that could then be processed by measuring signal strength (pixel intensity) to obtain the light source, transmittance, and absorbance spectra of the liquid sample. The homemade optical spectrometer consisted of: (i) a white LED as a light source, (ii) a cuvette or sample holder, (iii) a slit, (iv) a diffraction grating, and (v) a CMOS camera (webcam). In this study, various concentrations of a carbon nanoparticle (CNP) colloid were used in the particle size sample test. Additionally, a commercial optical spectrometer and tunneling electron microscope (TEM) were used to characterize the optical properties and morphology of the CNPs, respectively. The data obtained using the homemade optical spectrometer, commercial optical spectrometer, and TEM showed similar results and trends. Lastly, the calculation and measurement of CNP size were performed using the effective mass approximation (EMA) and TEM. These data showed that the average nanoparticle sizes were approximately 2.4 nm and 2.5 ± 0.3 nm, respectively. This research provides new insights into the development of a portable, simple, and low-cost optical spectrometer that can be used in nanomaterial characterization for physics undergraduate instruction.

Zero-dimensional Perovskite Magic-size Clusters play crucial roles in understanding and controlling nucleation and growth of semiconductor nanoparticles. However, their metastability behavior is a critical hindrance for reliable characterizations. Here, we report the first demonstration of using an excess amount of surface ligand and SiO2 as novel passivation for synthesizing the magic-sized clusters (MSCs) by the Ligand-assisted reprecipitation method. A synergetic effect between an excessed surface ligand and SiO2 inhibits the protonation and deprotonation reaction between amine-based and acid-based ligand, leading to enhanced PL stability. The obtained CH3NH3PbBr3 PMSCs/SiO2 retain 70% of its initial emission intensity in ambient conditions for 20 days. This passivation approach opens an entirely new avenue for the reliable characterizations of CH3NH3PbBr3 PMSCs, which will significantly broaden their application for understanding and controlling nucleation and growth of semiconductor nanoparticles.

Carbon nanoparticles (C-Dots) were synthesized using citric acid and urea as carbon and fuel source, and combustion reaction methods. The absorption spectral and morphology particles of C-Dots were investigated. The morphology describes the synthesis of small (<1 ?m) and monodispersedC-Dots. Thus, the C-Dots solutions has absorption spectral range of about 86% at visible light spectral. This study suggests that the as-prepared carbon nanoparticles (C-Dots) with particle size and absorption spectral tunability might be utilized as solar energy absorber material.Karbon nanopartikel (C-Dots) disintesis menggunakan asam sitrat dan urea sebagai sumber karbon dan bahan bakar, melalui reaksi pembakaran sederhana. Spektrum absorpsi dan morfologi partikel C-Dots diinvestigasi menggunakan UV-Vis Spectrometry dan analisis SEM. Hasil SEM menunjukan bahwa morfologi partikel C-Dots sangat kecil (<1 ?m) dan seragam. Selain itu, larutan C-Dots memiliki spektrum absopsi pada rentang sekitar 86% pada daerah cahaya tampak. Hasil studi ini menunjukan bahwa karbon nanopartikel (C-Dots) dengan ukuran partikel dan spektrum absorpsi yang dapat diatur, sehingga dapat digunakan sebagai material penyerap sinar matahari.

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