Karakterisasi Optik, Struktur dan Kandungan Unsur Karbon Amorf Berbasis Sekam Padi Terdoping Nitrogen untuk Potensi Aplikasi Fotovoltaik

Abstract

The increasing demand for renewable energy has encouraged the development of alternative semiconductor materials for photovoltaic applications. This study focuses on the synthesis and characterization of nitrogen-doped amorphous carbon derived from rice husk biochar using urea as the nitrogen source. The material was synthesized through carbonization, KOH activation, and nitrogen doping processes using three sample variations, namely non-thermally activated carbon (SM), carbon activated at 300°C (S300), and carbon activated at 500°C (S500). The objective of this research is to investigate the synthesis process and evaluate the optical, structural, morphological, and functional group characteristics of the synthesized materials. Characterization was conducted using X-ray Diffraction (XRD), Scanning Electron Microscopy–Energy Dispersive X-ray (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), and UV-Vis spectroscopy. The XRD results confirmed the amorphous nature of the carbon with the presence of calcite (CaCO₃). SEM analysis revealed a rough, porous surface with particle agglomeration, while EDX confirmed the presence of C, N, O, and other mineral elements. FTIR analysis indicated the successful incorporation of nitrogen through the presence of C–N, N–H, and C≡N functional groups. UV–Vis and Tauc plot analyses revealed that nitrogen doping shifted the absorption edge to longer wavelengths and reduced the band gap energy, indicating improved optical absorption characteristics. These results demonstrate that nitrogen-doped amorphous carbon derived from rice husk has modified optical and electronic properties, making it a promising candidate for photovoltaic applications.