RF, Optoelectronic & Sensor Devices

RF, Optoelectronic & Sensor Devices: Heterostructures, HEMTs, HBTs & Microwave Devices, LEDs, Laser Diodes & VCSELs, Photodiodes, APDs, Phototransistors & Solar Cells, Semiconductor Sensors & Hall-Effect Devices.

• Heterostructures, HEMTs, HBTs & Microwave Devices — Semiconductor devices for GHz and beyond. Learn heterojunctions and band alignment (type I/II/III), modulation doping and the two-dimensional electron gas, HEMTs (GaAs pHEMT, InP, AlGaN/GaN), transconductance and f_T/f_max, noise figure and power density, HBTs (wide-gap emitter or SiGe graded base, high injection efficiency, f_T and f_max), MESFETs, RF MOSFETs/LDMOS, transferred-electron (Gunn) devices and negative differential mobility, IMPATT/TRAPATT avalanche transit-time diodes, RF Schottky, PIN and varactor diodes, and device selection for LNAs, PAs, mixers and oscillators — with Python computing transit-time f_T limits, g_m/C_gs f_T, HBT f_max, and Gunn/IMPATT frequencies.
• LEDs, Laser Diodes & VCSELs — Semiconductor light emitters. Learn electroluminescence by radiative recombination in direct-gap materials, LED structures (double heterostructure, quantum wells, InGaN/GaN blue and phosphor-converted white, AlGaInP red), wavelength and colour, internal/extraction/external quantum efficiency and wall-plug efficiency, forward voltage, luminous efficacy, thermal effects and efficiency droop, LED drivers; then lasers: stimulated emission, population inversion, optical gain and the cavity, threshold current, slope efficiency and L–I curves, longitudinal modes, temperature sensitivity (T₀), modulation speed, edge emitters (Fabry-Pérot, DFB) and VCSELs — with Python computing emission wavelengths, EQE/WPE, LED resistors, laser output power and threshold vs temperature.
• Photodiodes, APDs, Phototransistors & Solar Cells — Turning light into current. Learn absorption and absorption depth, the photovoltaic and photoconductive effects, PN and PIN photodiodes (responsivity, quantum efficiency, dark current, junction capacitance, transit and RC bandwidth, photovoltaic vs photoconductive mode), avalanche photodiodes (gain, excess noise factor, ionisation ratio k), phototransistors, optocouplers and noise-equivalent power; then solar cells: equivalent circuit with series and shunt resistance, I–V and P–V curves, I_sc, V_oc, maximum power point, fill factor, efficiency, irradiance and temperature effects, and MPPT — with Python computing responsivities, APD excess noise, PIN bandwidth and a full solar-cell I–V solution with MPP and fill factor.
• Semiconductor Sensors & Hall-Effect Devices — Semiconductors as sensors. Learn the Hall effect (Lorentz force, Hall voltage, Hall coefficient and carrier-type determination), linear Hall sensors, Hall switches/latches, current sensing and position/speed sensing, other magnetic sensors (AMR/GMR/TMR overview); temperature sensors (diode/PTAT, thermistors NTC/PTC, silicon resistive), piezoresistive pressure/strain sensors and MEMS, photodetectors and image sensors, gas sensors (metal-oxide, FET-based), radiation detectors (PIN, Si drift, CdTe/CZT) — covering physical effect, structure, output, sensitivity, temperature effects, conditioning and applications — with Python computing Hall voltages, piezoresistive bridge output and PTAT/diode temperature signals.