How to get RAW Html code from my module?
It's not totally clear what you mean by 'from my module' but if you're asking how to get the HTML code of any Url into a variable in your module, you can use the drupal_http_request function. Below example comes from https://api.drupal.org/api/drupal/includes%21common.inc/function/drupal_http_request/7.x

$data = 'name=value&amp;name1=value1';

$options = array(
                'method' =&gt; 'POST',
                'data' =&gt; $data,
                'timeout' =&gt; 15,
                'headers' =&gt; array('Content-Type' =&gt; 'application/x-www-form-urlencoded'),
        );

$result = drupal_http_request('http://somewhere.com', $options);


You can also use curl via the cURL HTTP Request (chr) module.