Electronic Devi...

Consider an abrupt p-n junction at T = 300 K with doping concentrations of N_d = 3 × 10¹⁶ cm^-3 and N_a = 4 × 10¹⁵ cm^-3. At zero bias, the depletion region extending to the p-side is 0.447 μm. The depletion region extending to the n-side will be:

A GaAs LED radiates at wavelength 900 nm. If the current through the LED is 20 mA, the output optical power, with an internal quantum efficiency of 10% is ________ mW

The ratio of hole minority current to the electron minority current in an infinite p-n junction is 4. If conductivity on p-side is 1.4 S/cm and on n-side is 2.8 S/cm, then the ratio of diffusion length L_n and L_p (ie L_n/L_p) is _______.

Consider two pnp bipolar junction transistors. For first transistor when emitter to collector voltage is 5 V, V_EB is 0.85 V and emitter current is 10 A. (The β for this transistor is 15). Second BJT conducts with collector current of 1 mA and V_EB = 0.70. The ratio of emitter base junction area of first transistor to second transistor is ______.

If E_gE denotes the bandgap of emitter and E_gB denotes the Bandgap of Base. Then in order to achieve high gain β pf the transistor

A sample of GaAs doped with N_A = 10¹⁷ cm^-3. For GaAs, intrinsic concentration is n_i = 2.2 × 10⁶ cm^-3, mobility of electron is μ_n = 5300 cm² / V-sec, and mobility of hole is μ_p = 230 cm² / V sec.

If the sample is illuminated, an excess electron concentration of 10¹⁶ cm^-3 is generated.

A depletion type N-channel MOSFET is biased in its linear region for use as a voltage controlled resistor. Assume threshold voltage V_TH = 0.5 V, V_GS = 2.0 V, V_DS = 5 V, W/L = 100, C_OX = 10^-8 F/cm² and μ_n = 800 cm²/V-s. The value of the resistance of the voltage controlled resistor (in Ω) is _________.

The diffusion capacitance of a germanium PN junction diode is 10 nF at forward voltage of 0.5 V, then the diffusion capacitance of same PN diode at applied voltage of 1 V is.

Take η = 1, V_T = 0.0259 V

Consider an LED made of a semiconductor with \({E_g} =\sqrt{1.24}~eV\) and \(\frac{{d{E_g}}}{{dT}}\) = -5× 10^-4 eV/K. The change in the emitted wavelength if the temperature changes by 10°C is:

(Take hc = 1240 eV nm)

A T = 300 K, an n-type silicon sample contains a donor concentration N_d = 10¹⁶ cm^-3 and intrinsic concentration n_i = 1.5 × 10¹⁰ cn^-3. The minority carrier hole lifetime is found to be τ_p0 = 20 μs.

Which of the following conclusions for the given data is/are correct?

The resistivities of the two sides of an abrupt germanium diode are 2 Ω-cm (p side) and 1 Ω-cm (n side) at 300 K. Assume that the mobility of electrons and holes in germanium is μ_n = 3800 cm² / V-sec and μ_p = 1800 cm² / V-sec respectively, and intrinsic concentration n_i = 2.25 × 10¹³ cm^-3. Take kT = 25.9 meV. The value of built-in potential (in volt) is________. (Correct up to 2 decimal places)