We　investigated　the　carrier　injection　mechanism　in　InGaN/GaN　blue　light-emitting　diodes　by　growing　monolithic　dual-wavelength　multiple　quantum　1　wells　and　measuring　electroluminescence　spectra　at　different　current　densities　at　room　temperature.　During　the　epitaxial　growth,　V-defects　of;　different　sizes　were　intentionally　formed　in　the　active　region　area　by　controlling　the　growth　conditions.　We　found　that　the　size　of　the　V-defects　has　a　significant　effect　on　the　spectral　competition　of　dual-wavelength　emissions.　With　small　V-defects,　light　emitted　from　quantum　wells　near　p-GaN　is　dominant.　In　a　sample　with　large　V-defects,　quantum　wells　near　n-GaN　contribute　more　to　carrier　recombination.　The　hole　injection　depth　of　eight　pairs　of　quantum　wells　far　from　p-GaN　is　quantitatively　estimated.　We　attribute　the　different　behaviors　to　the　modulation　of　carrier　injection　depth　by　the　formed　V-defects.　(C)　2014　The　Japan　Society.　of　Applied　Physics