| 摘要 |
<p>PURPOSE:To facilitate photoluminescence measurement of a device whose width of a forbidden band is narrower at an upper semiconductor layer than at a lower semiconductor layer, by increasing selective degree of freedom of an external excitation light source. CONSTITUTION:Width of a forbidden band E1 for an upper semiconductor layer 1 and E2 for an lower layer 2 are given as E1>E2. When light energy E0>E1, the external excitation light 4 excites and luminesces the layer 1 with a wave length lambda1=ch/E2 from the layer 2. Although these two different rays with their wave length of lambda1 and lambda2, the ray 8 can be separated by means of an interference filter 9 which passes only lambda2, and the ray 8 is recieved by light measuring device 6. With this method, any light energy E0 that is larger than the width of the forbidden band of the layer 1 can be used as an external excitation light source, thus selection of a light source becomes easier. Photoluminescence of an active layer with the forbidden band width of around 1eV can also be measured by means of an Ar laser.</p> |
