All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
It is better and more appropriate not to have the Name of Allah; the name of His Prophet ; the Quran; or its interpretation as the wallpaper (background screen) of a mobile phone because its owner may enter the toilet with it, and it is Islamically disliked to enter the place of relieving oneself with something on which there is a mention of Allah unless it is covered. If it is covered, then it is not disliked; this is in order to honor the rites of Allah.
Based on this, it is better that the wallpaper be something else (other than what has been mentioned in the question) of Islamic slogans and similar permissible matters.
However, if a person chooses to have the Name of Allah or His Prophet or some verses of the Quran as a wallpaper (background screen) on his mobile phone, then he should be cautious when entering the toilet so that the screen does not appear when he is in there.
Allah knows best.