We investigate the photoluminescence ͑PL͒ properties of a thick InGaN single quantum well ͑SQW͒ in which an AlGaN ␦ layer is embedded. The ␦ layer offers an extra degree of freedom which may be employed to tune the emission wavelength. One of the most salient features of such a QW structure is that the long-wavelength tuning is feasible with lower indium composition. The ␦ layer also increases the wave function overlap between holes and electrons, shortening the PL lifetime. All the measurement

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... results are consistent with the numerical predictions. The QW structure could be of great importance in the design of long-wavelength lasers.