Fig. 1: OBJT operation.
a, Vertical stack configuration of the OBJT. b, Definition of active and parasitic currents and lateral geometric parameters in the OBJT. c, The OBJT device under a polarized microscope. Scale bar, 100 μm. d, Transfer characteristics of the OBJT device with blocking layers deposited on top of the base electrode for different VCE: solid lines give the absolute collector current IC, dashed lines give added current ∆IC = IC − IC0. e, The corresponding differential amplification for the device in d. f, Definition of the biasing and measurement setup for all OBJT curves and representation of the equivalent circuit of the OBJT containing active and parasitic components analogous to the currents defined in b: DB1, direct base–collector diode with IBC leakage current; DB2, direct base–emitter diode with IBE leakage current; RCE, direct emitter–collector overlap with IC0 output off-current. g, Transfer characteristics of the OBJT device without blocking layers deposited on top of the base electrode at different VCE: solid thick lines, absolute collector current IC; dashed lines, added current ∆IC = IC − IC0; solid thin lines, absolute direct current amplification. h, Absolute and area-normalized capacitance of an individual rubrene-based pin (input) diode at different biasing conditions and varying measurement frequencies. The active area is 100 × 100 μm2. i, Transition frequency estimation from transconductance.
