Research On Performance Improvement Of Heterojunction Optoelectronic Devices Based On InGaAs

In recent years,optoelectronic devices represented by InGaAs and InP have played a pivotal role in the fields of military,communications,medicine,and outer space exploration.In this thesis,it is studied the performance of InGaAs-based optoelectronic devices and their optimized structure.The semiconductor device simulation tool Silvaco was used for modeling and simulation,and then the experimental data were fitted.The existing structure was optimized and the results were analyzed.After improving the structure of the device,the output current of the one-sided junction detector is increased,the dark current of the superlattice detector is reduced,and the short circuit current and power of the solar cell are further improved.In this thesis,it is given explanations of the phenomenon.The improved detector can get more accurate output results;and the improved solar cell can make better use of sunlight.The improvement methods are also relatively innovative and provide some reference for future research.The main contents are as follows:First,the principle and performance of the one-side junction photodetector were studied,and then its structure was improved by inserting a cliff layer into the absorption layer of the one-side junction photodetector in order to obtain a larger current.On this basis,further increasing the carrier concentration of the cliff layer can continue to increase the current;increasing the thickness of the collector layer,the current also increases accordingly.The impact on bandwidth is also analyzed in this chapter.Then a new type of superlattice photodetector is simulated.InGaAs/InAs superlattice is inserted into the intrinsic layer of the PIN structure,and the position of the superlattice is optimized.After changing the position of the superlattice,the dark current was reduced from dark current from 1.3×10-3A/cm2 to 3.7×10-5A/cm2.The results show that placing the superlattice on top of the intrinsic layer can minimize the dark current of the photodetector.Similarly,after changing the number of superlattice layers,the dark current was reduced from 1.49×10-4A/cm2 to 3.3?10-5A/cm2.In addition,the thickness of the superlattice was changed,and the dark current was reduced from 1.02×104A/cm2 to 3.25×10-5A/cm2.The data proves that increasing the thickness can reduce dark current.Finally,a new type of multi-quantum well solar cell is studied.InGaAs/InGaAsP quantum wells are inserted into the intrinsic layer of the PIN structure,the layers and position of the quantum wells are optimized.After changing the layers of the quantum well,the short-circuit current increased by 4%from 25.4 mA/cm2 to 26.3 mA/cm2.In addition,after adding an anti-reflection layer on top of the quantum well solar cell,the short-circuit current increased by 8.8 mA/cm2 on the basis.Obviously,InGaAs/InGaAsP quantum well solar cells better absorb incident sunlight.In addition,the effect of different quantum well positions in the intrinsic layer on the short-circuit current is also discussed.The results show that placing the quantum well on top of the intrinsic layer can maximize the power of the solar cell.