General discussion on PHP
PHP is a server side language while responsive website is made using client side language. So it does not matter what you use in serverside PHP, Nodejs, Java etc you can make responsive website for frontend using HTML CSS
To make a website design in PHP is not a good option because while we decide to make SEO of the website, there its take more time as compared to latest website development platforms such as WordPress, Wix and etc.
PHP is just a scripting language. It has nothing to do with design. Website design is created using HTML and CSS. So, you can definitely create a responsive website. The recommended framework is Bootstrap.
Responsive webdesign is not related to PHP or any other language. It is mainly based on the theme u are undertaking and whether it supports the responsiveness feature. U can check my assignment help site where u can see its responsive and also on PHP framework.