| Summary: | 碩士 === 國立交通大學 === 理學院碩士在職專班應用科技學程 === 97 === InGaAsP was used to be adopted in the long-term fiber optical communication, but this material is highly sensitive to heat, which requires coolers to maintain its stability and thus increases the cost of packaging. Two new systems, InGaAsN and AlGaInAs, are found to have more advantages and appeal to more academic attention. The InGaAsNSb system, with a large amount of band offset ratio (△Ec: △Ev = 7：3 or 6：4), is particularly dominant, based on its low-sensitivity to heat and improvement in electronic current overflow. Moreover, the properties of its electronic and heavy-hole effective mass are appropriate for the development of VCSEL. In addition, the cheaper GaAs substrate will surely lower the cost and bring a promising future.
This thesis aims to explore the optical properties of InGaAsNSb quantum wells. For semi-conductor, energy band diagram is a vital property, which limits the location of carriers and is helpful in calculation. Through the measurement of PL temperature, we intend to investigate the effect of N and Sb on optical properties of InGaAs/GaAs quantum wells. The result shows that adding 1% of N in In0.33Ga0.67As quantum wells will increase the strength of PL in different temperature and that the wavelengths have red shift phenomenon. As a result, we can infer that the input of N enables the sample structures to partially reduce the compressive strain and drops the optical properties so as to form red shift. With the input of Sb into the quantum wells, the wavelengths of the sample have no distinctive changes at 300K. When the temperature drops to 40K, the spectrum in the sample of InGaAsNSb quantum wells generates a wavelength at about 1300 nm, much stronger than 1200nm and with narrower FWHM (Full Width at Half Maximum), which proves the influence of Sb. Moreover, in the InGaAsNSb energy state, its FWHM is narrower than the other two peaks and the temperature influence on its wavelengths is more distinctive than that of no defect states. Therefore, we may infer that with the increase of Sb, the wavelengths of the sample have no obvious change at 300K. However, when the temperature drops to 40K, adding more than 30% of Sb will greatly lower the strength of the wavelengths in the spectrum of InGaAsNSb quantum wells sample. As a result, we conclude that although Sb can effectively red-shift the wavelengths of quantum wells to 1300nm, more than 30% of Sb will increase the compressive strain and make the quantum wells slack so as to cause many defects on the interface and lower the performance of quantum wells.
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