Light-emission and degradation characteristics of InGaAsP/lnP heterostructures

A study was made of double heterostructures fabricated by liquid phase epitaxy and emitting at wavelengths in the range 1.06–1.6μ. The maximum values of the external efficiency reached 10% at the wavelength of 1.06μ and 5% at 1.3μ. A study was made of the homogeneity of the emission pattern by visualization of the distribution in the near-field zone with the aid of an infrared television microscope. This revealed dark spots formed as a result of ageing of the heterostructure. It was found that when a certain dose was reached, the radiation defects stabilized the output power of heterostructures over a considerable operating period. Accelerated life tests estimated that the service life should be at least (60–100)×10³h.