Semiconductor materials – why silicon is most widely used Assertion (A): Silicon is the most favoured semiconductor for electronic devices. Reason (R): The peak inverse voltage (PIV) rating of a silicon diode is higher than that of a comparable germanium diode.

Introduction / Context:
Silicon dominates modern semiconductor technology. Understanding the underlying reasons helps students connect material properties to device performance and manufacturing practice.

Given Data / Assumptions:

• Comparison is between crystalline silicon and germanium devices of similar geometry.
• PIV refers to the maximum reverse voltage a rectifier can withstand without breakdown.
• Consider practical device behavior including leakage and thermal stability.

Concept / Approach:

Silicon has a larger bandgap (~1.12 eV) than germanium (~0.66 eV), leading to far lower intrinsic carrier concentration at room temperature. This provides lower leakage current, better high-temperature operation, and higher breakdown strength, which often translates into higher practical PIV for silicon rectifiers. However, silicon's overall dominance is due to a broader set of reasons: abundant availability, mature processing, excellent native oxide (SiO2) enabling MOS technology, and cost/performance scaling.

Step-by-Step Solution:

Verification / Alternative check:

Historic transitions from germanium to silicon coincided with the rise of planar processing and MOSFETs, enabled by high-quality SiO2—evidence that the oxide and stability advantages, not PIV alone, drove adoption.

Why Other Options Are Wrong:

(a) Overstates the explanatory power of PIV alone. (c) R is not false. (d) A is not false; silicon's dominance is well established.

Common Pitfalls:

Confusing a single device metric with the wider set of materials and manufacturing considerations that determine technology choices.

Final Answer:

Both A and R are true but R is not the correct explanation of A