Why does character

Question

I'm using PHPExcel in my Yii2 App. In my Excel file, there's a cell that contain data like this

Then I try to printout in screen using print_r and then I got array result like this . It should be Array ( [0] => 52034563 [1] => Chemical Books<S [2] => EAS [3] => A1 [4] => [5] => 00000_S [6] But, in the result the Index 2 is missing, and the Chemical Book<s become Chemical Books, and then all the array got Black Line.

But when I remove the <S, the array result has complete index and doesn't has Black Line.

Why does it happen, and How do I can make the PHPExcel can read the Excel data well even the data contain <S ?