Hi,
As there is no hotkey for the sleep mode, however you can follow the steps below to create a shortcut for sleep mode that will help you in the same way as hotkey.
To create a shortcut that will execute the sleep command in Windows 7:
a) Right Click in the desired location (On the Desktop or in a folder).
b) Select New > Shortcut.
c) In the “Type the location of the item” field enter the following
Rundll32.exe Powrprof.dll,SetSuspendState Sleep
d) Click Next
e) This will create a shortcut with the name rundll32,
f) Right Click the shortcut, select Rename and type in Sleep.
You can now open this shortcut whenever you desire to put your computer into sleep mode.
Note: You can replace the default icon with a Shutdown one by:
a) Right Click the created shortcut, select Properties > Change Icon.
b) Navigate to this link in the **“**Look for icons in this file:” field:
c) %SystemRoot%\windows\system32\SHELL32.dll icons.
d) Find the desired icon.
e) Click Ok.