We report the growth of In(Ga)As quantum dots (QDs) on In0.48Ga0.52P layers with and without GaAs spacer layers using solid-source molecular beam epitaxy. We can grow high quality and high density In0.4Ga0.6As and InAs QDs on In0.48Ga0.52P layers. In0.4Ga0.6As QDs with 2 nm GaAs spacer layers have high uniformity, which is confirmed by performing a photoluminescence measurement with a full-width at half maximum of 24 meV. We can control the energy difference between the In0.48Ga0.52P conduction band and the QD energy state by employing GaAs spacer layers and InAs QDs, which is a useful technique for realizing optimal intermediate-band solar cells fabricated using In(Ga)As QD structures in an In0.48Ga0.52P matrix. (c) 2013 Elsevier B.V. All rights reserved.