The document discusses the design and simulation of indium gallium nitride (InGaN) multijunction tandem solar cells, highlighting their tunable band gap and high conversion efficiencies. Numerical simulations indicated maximum efficiencies of 25.02% for single junction, 35.45% for double junction, and 42.34% for triple junction solar cells, with a notable thermal stability indicated by a temperature coefficient of -0.04%/°C. The research emphasizes the potential of InGaN materials in achieving higher efficiency and stability in solar energy applications.