Question

With fall of temperature, the forbidden energy gap of a semiconductor

(a) increases

(b) decreases

(c) sometimes increases and sometimes decreases

(d) remains unchanged​

Answer 1

Answer:

ʜᴇʀᴇ ɪs ʏᴏᴜʀ ᴀɴsᴡᴇʀ ⬇️

Explanation:

ғᴏʀʙɪᴅᴅᴇɴ ᴇɴᴇʀɢʏ ɢᴀᴘ ɪɴ sᴇᴍɪᴄᴏɴᴅᴜᴄᴛᴏʀs ɪs ᴏғ ᴛʜᴇ ᴏʀᴅᴇʀ ᴏғ ᴋᴛ. sᴏ ᴀs ᴡᴇ ɪɴᴄʀᴇᴀsᴇ ᴛʜᴇ ᴛᴇᴍᴘ, ᴇʟᴇᴄᴛʀᴏɴs ғʀᴏᴍ ᴛʜᴇ ᴛᴏᴘ ᴏғ ᴛʜᴇ ᴠᴀʟᴇɴᴄᴇ ʙᴀɴᴅ ᴡᴏᴜʟᴅ ɢᴀɪɴ ᴛʜᴇʀᴍᴀʟ ᴇɴᴇʀɢʏ ᴀɴᴅ ɢᴇᴛs ᴇxᴄɪᴛᴇᴅ ɪɴᴛᴏ ᴛʜᴇ ᴄ.ʙ, sᴏ ʙᴀɴᴅ ɢᴀᴘ ᴡᴏᴜʟᴅ ᴅᴇᴄʀᴇᴀsᴇ ᴡɪᴛʜ ɪɴᴄʀᴇᴀsᴇ ɪɴ ᴛᴇᴍᴘ. ʜᴇɴᴄᴇ ғᴏʀʙɪᴅᴅᴇɴ ᴇɴᴇʀɢʏ ɢᴀᴘ ᴏғ ᴀ sᴇᴍɪᴄᴏɴᴅᴜᴄᴛᴏʀ ᴅᴇᴄʀᴇᴀsᴇs ᴡɪᴛʜ ɪɴᴄʀᴇᴀsᴇ ɪɴ ᴛᴇᴍᴘᴇʀᴀᴛᴜʀᴇ. ᴛʜᴇʀᴇғᴏʀᴇ ᴏᴘᴛɪᴏɴ ʙ ɪs ᴄᴏʀʀᴇᴄᴛ.

Answer 2

The forbidden energy gap of a semiconductor (b) decreases as the temperature falls.

Explanation:

• The energy difference (in eV) between the top of the conduction band and the bottom of the valence band in any material, whether it is a metal, an insulator, or a semiconductor, is known as the forbidden energy bandgap.
• The conduction band and the valence band in semiconductors are separated by a tiny energy difference of roughly 1 eV. This is a little energy differential that may be compensated for via thermal agitation.
• The temperature affects the energy gap of semiconductor material. As a result, as the temperature rises above room temperature, the forbidden energy gap shrinks. The equation describes the relationship between the forbidden energy gap and temperature:

$Eg(T)$ ≅ $Eg(0)-\alpha T^{2}/T+\beta$

where,

$Eg_(T)$ is the semiconductor's forbidden energy gap at temperature T.

$Eg_(0)$ is the semiconductor's intrinsic forbidden energy gap.

$\alpha$ & $\beta$ are constants.

Hence, the gap decreases with the increase in temperature.