Quite simply, no, the backslash is not used in 'proper' English. It used in computing but not in written English.
The slash (sometimes called the forward slash now to define its difference from the backslash) is part of English writing, although it is not used a huge amount.
It doesn’t have a large role in formal English, but it’s used in specific cases. The forward slash ( / ) is used to show a line break when you're writing a poem, play or song. There should be a space before and after the forward slash.
A slash can show a line break in poem, song, or play, usually if several short lines are being written together on one long line. Remember to put a space after the slash.
People sometimes employ the forward slash in place of the word 'or.' For example: Right / wrong, good / bad.