Semiconductor light emitting device

A semiconductor light emitting device, comprising:

• a substrate;
• and
• a multi quantum well layer provided on the substrate,
• the multi quantum well layer including a plurality of InGaAs well layers and a plurality of barrier layers, the plurality of barrier layers each being made of AlGaAsP mixed crystal represented by a formula AlzGa1-zAs1-yPy(0≤z<1, 0<y<1), the InGaAs well layers and the barrier layers being stacked alternately in a first direction from a substrate toward the multi quantum well layer, the plurality of barrier layers including first barrier layers and second barrier layers, a group of the second barrier layers being provided next to a group of the first barrier layers,
• wherein the first barrier layers each include a first AlGaAsP mixed crystal represented by a formula AlzGa1-zAs1-yPy(0≤z<1, 0<y<1) and the second barrier layers each include a second AlGaAsP mixed crystal represented by a formula AlzGa1-zAs1-y2Py2 (0≤z<1, 0<y1<1<y2<1);
• or
• wherein the first barrier layers have first thicknesses in the first direction, respectively, and the second barrier layers have second thicknesses in the first direction, respectively, the second thicknesses being larger than the first thicknesses.