Creating a new PHPExcel Object.

$this->PHPExcel = new PHPExcel();

Creating a new sheet: $this->activeSheet = $this->PHPExcel->createSheet(); Setting the title: $this->activeSheet->setTitle($title);

Getting/setting the active worksheet.

$this->activeSheet = $this->PHPExcel->getActiveSheet();

$sheetIndex = 2;
$this->PHPExcel->setActiveSheetIndex($sheetIndex)

Setting the width of a specific column.

$this->activeSheet
    ->getColumnDimension($colString)
    ->setWidth($width);

Setting the default column width/row height for a sheet.

$this->activeSheet
    ->getDefaultColumnDimension()
    ->setWidth($width);
    
$this->activeSheet
    ->getDefaultRowDimension()
    ->setRowHeight($height);

Setting default styles for the active sheet

$this->activeSheet
    ->getDefaultStyle()
    ->applyFromArray($this->defaultStyle);