AlGaInAs GRADED-DAP GUNN DIODE

Abstract

Gunn diodes are the active elements for generating electromagnetic waves in the millimeter range. An urgent task of today is to increase their cutoff frequency and output power. One of the ways to do it is to use graded-gap semiconductors. The paper presents the results of numerical experiments on the electromagnetic waves generation with the help of Gunn diodes based on graded-gap AlGaAs-GaAs-InGaAs compound. The numerical simulation has been conducted by means of the temperature model of intervalley transfer of electrons in the graded-gap semiconductors. The length of the diode active area was 2.5 mm with the concentration of ionized impurities therein 1016 cm–3. We have shown that the AlGaAs-GaAs-InGaAs-diodes can be used as active elements for generating electromagnetic oscillations in the millimeter wave range. In GaAs-InxGa1–xAs- and Al0.2Ga0.8As-GaAs-InxGa1–xAs-diodes the output power increases almost linear with InAs percentage in the range from 0 to 50 %. As it turned out GaAs-Ga0.5In0.5As-diode has the greatest value of the output power Р = 12,2 kW´cm–2 at frequency of f = 45 GHz and efficiency of h = 10.5 %. Al0.2Ga0.8As-GaAs-In0.5Ga0.5As-diode has the greatest generation efficiency of h = 11,3% at Р = 10.6 kW´cm–2 and f = 41 GHz output power and generation efficiency of Al0.2Ga0.8As-GaAs-diode in 2 to 3 times lower than the parameters of mentioned above diodes. Our findings extend the knowledge of the physical processes of carrier transport in complex semiconductor structures and can be used for technological development of new high-performance devices based on A3B5 semiconductors.

Keywords

• domain
• generation efficiency
• graded-gap semiconductor
• gunn diode
• intervalley electron transfer
• output power
• temperature model
• terahertz electronics