How to increase columns in PHP excel - php

Question

I am making dynamic columns and my columns are 1000+ , can anybody guide me how to increase columns in PHPexcel. How can I increase my column length while creating dynamic columns? or Is there any other way For your reference I am showing my code below:
private function _buildExcellTableData(ExportExcel $excel)
{
$excel->row++;
$excel->row++;
$sheet = $excel->excel->getActiveSheet();
$sheet->setCellValue('D1', 'Role Requirement Report');
$header1 = $sheet->mergeCells('D1:G1')->getStyle('D1');
$header1->getFont()->setSize(18)->setBold(true);
$header1->getFill()->setFillType(\PHPExcel_Style_Fill::FILL_SOLID)->getStartColor()->setRGB('E6E6E6');
$alpha = 'B';
$countCells = count($this->data['roles']);
$header = $sheet->getStyle('A'.$excel->row);
$header->getFont()->setBold(true);
$header->getFill()->setFillType(\PHPExcel_Style_Fill::FILL_SOLID)->getStartColor()->setRGB('E6E6E6');
$sheet->getStyle('A'.$excel->row)->getAlignment()->setHorizontal(\PHPExcel_Style_Alignment::HORIZONTAL_RIGHT);
$sheet->getColumnDimension('A')->setAutoSize(TRUE);
$sheet->setCellValue('A'.$excel->row, 'Roles/Requirements');
$rolesIds = array_map(create_function('$o', 'return $o->id;'), $this->data['roles']);
foreach($this->data['roles'] as $key=>$value)
{
for ($i = 0; $i < $countCells; $i++)
{
$sheet->getColumnDimension($alpha)->setAutoSize(TRUE);
$sheet->setCellValue($alpha.'6',$value->title);
}
$alpha++;
}
$row_start = $excel->row;
foreach ($this->data['rolesrequirement'] as $key=>$row)
{
$excel->row++;
$sheet->setCellValue('A' . $excel->row, $row->title);
$roleCheck = array_map('trim', explode(',', $row->roleid));
$alpha = 'B';
for ($i = 0; $i < $countCells; $i++)
{
$value = (in_array($rolesIds[$i], $roleCheck)) ? 'x' : '';
$sheet->getStyle($alpha.$excel->row)->getAlignment()->setHorizontal(\PHPExcel_Style_Alignment::HORIZONTAL_CENTER);
$sheet->setCellValue($alpha.$excel->row, $value);
$alpha++;
}
}
$row_style = $sheet->getStyle('A'.$row_start);
$row_style->getBorders()->getAllBorders()->setBorderStyle(\PHPExcel_Style_Border::BORDER_THIN);
}
Thanks in advance!