Several things are wrong here.
First, before putting a command in crontab, check that it works by running it yourself.
Second, if you want the html code generated by a (dynamic) php webpage, you must access trough the web server, not reading the php from from the filesystem. In the case of a php webpage, an alternative (not necesarily equivalent) would be to just invoke the php interpreter from the CLI:
Third, no need to you use lynx (a text browser) for that, go wget:
Perhaps you must change the url, that depends on your webserver configuration. Load it first in your web browser to check.