Non-polar a-plane InGaN films were grown on a r-plane sapphire substrate by plasma assisted molecular beam epitaxy (PAMBE). The growth temperature and Indium flux were varied to optimize the desired composition of In0.17Ga0.83N on the (11-20) a-plane GaN epilayer grown on a (1-102) r-plane sapphire substrate. The structural, morphological and optical properties of the optimized composition has been studied. It was found that highly a-axis oriented InGaN epilayers with no phase separation can be grown at 550 °C with In/Ga flux ratio of 0.61. The composition of indium incorporation in single phase InGaN films was found to be 17% as estimated by high resolution X-ray diffraction. The room temperature band gap energy of single phase InGaN layers was determined by photoluminescence measurement and found to be around 2.36 eV. The rectifying behavior of the I-V curve indicates the existence of Schottky barrier at the InGaN and GaN interface. The Schottky barrier height (φb) and the ideality factor (η) for the InGaN/GaN heterostructures were calculated.