This paper reports the MOVPE growth of InxGa1–xN (x ∼0.5) on Si(111) with a pn junction on the surface. By optimizing growth temperature and TMI/(TMI+TEG) molar ratio, InGaN films with In content up to 0.5 are successfully grown without phase separation and metallic In incorporation. No significant differences in tilt fluctuation in grown InGaN are found among three different substrates; GaN/α–Al2O3(0001) template, p–Si(111) and n‐Si(111) with a p‐type layer on the surface. The tilt fluctuation increases with increasing In content in InGaN and shows the maximum at around In composition 0.5. The n‐InGaN/p–Si structures show good ohmic characteristics and the resistance obtained from the slope of I‐V curves is markedly reduced with increasing In content in InGaN. The Si pn junction beneath the In0.42Ga0.58N layer behaves well as a solar cell with an InGaN filter. For both n‐InGaN/p‐Si and n‐InGaN/pn‐Si structures, the presence of an AlN interlayer between the epilayer and the substrate does not have a significant contribution to the series resistance. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)