Although it's not an SAPUI5 MVC structured application, there's nothing wrong with your code.
If you run it from Google Chrome, do you run it from a webserver, or as a local HTML file (Something with URL like file:///myfolder/Invoice1.html) ? If run locally, then you should've definitely seen errors in the console, stating something like 'sap-ui-core.js not found' or similar.
Either put your file on a local/remote webserver (or use the one Eclipse provides and use that URL), or adapt the URL to sap-ui-core.js in your index.html file so it points to an absolute path rather than a relative path.
As for the MVC stuff, the links already provided by Jason should give sufficient help.