This is the 2D companion to the 3D particle-swarm channel view: instead of watching electrons drift through a rendered 3D device, this reads the same transport physics off four analytic 2D plots that a real device engineer would actually use on a datasheet or in a TCAD report.
Top-left — output characteristics. Family of IDS-VDS curves at fixed VGS values, with the live bias point marked. Each curve is the same current formula the readouts use:
I_DS = q·n_s0·f_ns(V_GS)·v(E)·100 [mA/mm]
E = V_DS / L_channel (uniform-field approximation)
Bottom-left — velocity-field curve. The Caughey-Thomas relation that bends drift velocity into saturation at high field, drawn for both the current lattice temperature and a 300 K reference:
v(E) = μ₀(T)·E / [1 + (μ₀(T)·E / v_sat)ⁿ]^(1/n)
μ₀(T) = μ₀(300K)·(300/T)^1.5
Top-right — conduction-band cross-section. A depth cut through the AlGaN barrier into the GaN buffer at the gate. The 2DEG lives in the triangular quantum well right at the heterojunction; raising VGS toward pinch-off (Vth ≈ −3.5 V) lifts that well back above the Fermi level, so the shaded electron population — driven by the exact same f_ns(V_GS) fraction as the readouts — shrinks and the animated jitter dots thin out.
Bottom-right — channel field profile. The local field-enhancement factor along the channel (source → drain) used by the 3D scene's particle speeds: flat in the ungated access region, a mild step under the short gate, and — when "drain field crowding" is on — a rise toward the drain edge that scales with VDS, reflecting the real short-gate/long-drain-access HEMT layout used for high breakdown voltage.
- VGS — sets f_ns, the surviving 2DEG fraction (capacitive depletion, pinch-off below Vth).
- VDS — sets the channel field, hence drift velocity, saturation and drain-side crowding strength.
- T — phonon scattering lowers μ₀, flattening the v-E curve and shifting the operating point.